L.,
I went through a similar experience when my daughter was an infant (she is now 10 years old). When we tried to give her a bottle at about 4 months, she arched her back and cried. She would not accept a bottle. My husband and I came up with the bright idea of trying to give her a bottle when she woke up in the morning. We agreed that I would not nurse her until she took a bottle from my husband. Big mistake. She screamed and cried for over 1/2 hour. I sat in the other room until I could not take it any more and then I nursed her. We decided to go to a lactation consultant, because, I too, was desperate.
Her advice...
Do not wait until the baby is hungry to try to force the bottle on her.
After the baby has nursed, but before she is due for the next feeding, have someone place her on the floor (you should leave the house or at least leave the room). Place her on her back and give her a bottle w/ breastmilk. Do not expect her to drink. She told us that babies will naturally put objects up to there mouths. After "playing" with the bottle for a while, a few drops fell out and she figured out it was the same stuff that mommy was feeding her, only it was in a different container.
Again, when she isn't absolutely starving, have someone else give her a bottle. Face the baby away from that person (so that she is not facing the person's chest). The baby should be "seated" on the person's lap, facing away from him/her.
I believe my daughter took the bottle w/in a day or two.
Try looking up some info. on the internet(e.g., search for baby refuses to take bottle). If they offer these suggestions and others, I am sure your baby will be taking a bottle in no time. Good luck
L. B.