JPMorgan Chase & Co. Credit Card Complaint

JPMorgan Chase & Co. Credit card department,

Balance transfer Connecticut

I did a balance transfer with Chase and I made a purchase which I paid In full before the billing statement. They charged me purchase interest fee and now they tell me that I need to pay the balance in full to avoid any future interest.if that 's the case what 's was that whole sham of 0 % apr.