AT&T U-verse

I cancelled service at my house, received a billing two weeks later, and then received a statement with a credit on the account. I called the customer service # and was told that they can't access my account because it's closed. I was also told that I should be getting my credit refunded after two billing cycles. I told them two months of holding my $ wasn't ok and was hung up on when they were looking up info. Absolutely terrible!!!!!