Citibank Credit Card Complaint

Citibank Credit card department,

Balance transfer North Carolina

I have a 0 % APR promotional balance transfer on my credit card with Citicard. In the same billing period, I made additional purchases besides the balance transfer. I paid the minimum amount due from the monthly statement, PLUS the entire amount of the non-promotional purchases. Citicard charged me interest, saying that it was because I had not paid the statement balance in full, including the balance transfer amount. When I referenced the CARD act provisions that say that any amount paid above the minimum amount due must be allocated to the highest interest balance ( i.e. the new purchase balance and not the balance transfer ), they said I was wrong and expressly stated that their policy was the opposite. I want to make sure I 'm right in that I should not have been charged interest. I saw there are exceptions to this for special debt payment agreements, but I do n't think my account falls into this exception. Furthermore, the customer service rep would not explain the math to me of how they arrived at the interest charged - it does n't make sense to me.