preface_
ALL CONURES ARE LOUD. PERIOD. FULL STOP.
whoever told you there was a quiet conure misinformed you. Quiet for a CONURE, yes a green is, say, compared to a sunburst. For a parrot, no. Conures are among the loudest relative to their size of all pet parrots. Lorikeets, conures, very loud.
Firstly, the bird is scared.. but it wants YOU as its calming object. Good sign. Means the bird will be your friend. If bitten DO NOT react. Very gently grab the beak, like you would a baby's hand, and say no. Then kiss the bird gently on the beak. Most friendly birds will learn like that. Returning to cage does not compute. If bitten HARD with intention to truly hurt (note many early bites are out of fear) put the bird on the ground for 30 seconds, make a baby like ouch! in a high pitch so it knows it hurt you. then pick it back up. Remember he does not WANT TO hurt you he is scared and confused. Never retain malice for a few minutes like you would say for the next 4 mins with a dog 'no that was bad'. Immediately return to normal loving contact after you correct the parrot. They do not understand 'extended' reactions and will become confused and think you dislike them.
Tell your neighbors they're just going to have to deal with it. Are you violating local noise bylaws? If not I would just ignore the neighbor. That's what Id do. Don't cover her cage to make her quiet. YOu decided to get a bird. Birds are loud. Whoever told you conures are quiet lied. Senegals are relatively quiet and about the same size. Greys are very large, but also very quiet. Love Birds (a small parrot species) are also relatively very quiet. They really do prefer to be kept in pairs though but they dont need a huge cage and 2 lovebirds equal the cost of one conure. Also a very good option if you are looking to change to a more appropriate bird for you. Conures chirp and scream a lot. It is their nature. You will have to accept it. As time goes by the SCREAMING will stop. SPend a lot of time with the bird let it live on your shoulder most of the day. It sounds lonely and in need of a friend connection which it wants with you, again a good sign. EVENTUALLY screaming will stop but loud vocalizations never will. And they are L O U D. Again the conure is a LOUD BIRD. Period. It will be loud for the next few decades.
Covering the cage for silence etc is the wrong move. You do not do that to your bird. Covers are for at night so he can sleep in peace. Your bird wants to be part of your family and sit on your shoulder all the time. That's what conures want. If you still can, and you are CERTAIN you will never tolerate the noise, try a senegal parrot as they only whistle and chirp and RARELY if ever scream. I suggest you stick with your conure though and learn to accept who he is rather than try to change him. He's loud, but he just wants you to be his friend.
Enjoy your new life long friend.
Conures=loud. Fact. Period.
[ame="http://www.youtube.com/watch?v=3_KHKyYhbTs"]My pet Conure - YouTube[/ame]
^ notice his "IM HAPPY! SQUEEEK SQUEEK" is even insanely loud, and thats a happy call. It's blindingly loud. Look forward to up to 40 years of that I promise you.
This is all conures want. A big protective bird (you) to hang out with, be fed by, cuddled. That's it. They love to be held. It is a very good bird to have as a friend but you must learn to tolerate the noise. See, even this one is loud and he is super happy.
Please make sure you can tolerate this. if you can not it is best to return the bird BEFORE you bond. A Senegal is not a bad choice as I barely even hear mine all day. They also are calmer. But I suggest you learn to make peace with your Con. If you are absolutely sure 1) you can not take it 2) your neighbors can not take it, please get a Senegal instead as they are quiet unless upset and usually only whistle or tweet at a reasonable volume.
PS Buy BARRONS parrot owners handbook/guide to a well behaved parrot. goldmine of info.
Birds are ultra social and want to be with you ALL the time, except (some birds) to eat and (all birds) to sleep. Otherwise they want to be in the flock (you and your family)
Here is my senegal.
Remember in the wild they live in groups between dozens and thousands, with many friends, and are always cuddling and chatting.
[ame="http://www.youtube.com/watch?v=7CekOQ0gme8&feature=related"]Feeding the Birds - YouTube[/ame]
A group of wild Lorikeets (parrot relative) in the wild. Note the size and how much they communicate. Despite common misconceptions, a parrot wants to be with you more than a dog does. It wants to glue itself to your shoulder, have a bite of your muffin, etc.
Have you tried this trust exercise? WIth the bird out on your finger, close your eyes, open your mouth, and put your face against it. I don't think it'll bite. Usually they gently touch your mouth. Being up against the parrot with eyes closed means "I trust you with my life" and will help him bond to you. Conures can not bite very hard anyways. Surprisingly weak beak IMO.
DO NOT BOND with this bird if you will not keep it and if you want to switch do it NOW while you still can but in future plz research first. And get a TRULY quiet bird. Parrotlets (very tiny parrot species) for instance, are not too loud, but you must get one from a breeder. They become frightened at pet shops. From a breeder it will be a perfect (quieter) pet. Senegals are quiet. Greys are quiet. Just because the bird is the size of a chicken does not increase care difficulty. Price yes. Cage size yes. And it eats 6x the food.
Your Conure will be
loud for the next 40 years. Remember this. It also sounds like he wants to make friends with you. You must make a decision. Today IMO. Good luck. I am sorry you were misinformed. And you really were. Conures are all loud.
SO, cliff notes:
Buy from breeders, not pet shops, WHENEVER possible
. Much healthier, meet parents, bird has had an easy life so far, will be calmer
Conures are all loud. He will always be loud. If you can put up with it, he will be a great friend for you. It is a very well mannered and fun bird and very friendly. It's MAJOR down side is that it is louder than an F18.
If you can't take it, return him immediately before a bond forms. The SQUEEEEEEEEEEK at 1000db will NEVER stop. That's just their call. It's just who they are.
Do not cover cage in day time
Do not place bird in cage over bite. Only lovingly correct or if hard bite place on floor 60 secs then resume normal loving interaction
Never yell at the bird for any reason. Gentle correction followed by good bird. I have never seen a need to be mean or rough. Be loving and tender. They are smart enough to learn to love and respect you gently.
He will eventually want to try to clean your hair and your beak (the inside of your mouth). You're gonna have to put up with it its how they show they care 
If you want a quiet bird, look into Senegal, Lovebird, African Grey, pacific parrotlet. All "higher thought" birds << like this will form a loving bond with you and learn to speak. Otherwise, enjoy your loud F18 (they are lovely pets minus the noise) for the next few decades
But there ARE quiet birds. You DONT have to keep the loud bird if it will cause havoc among neighbors and be difficult for you. And you can never punish it for being loud like it is supposed to and you already have. I suggest you change birds. I think it is the right to do. I have listed some quiet friendly birds. They are all affordable. Only the grey is expensive.