JPMorgan Chase Credit Card Complaint

JPMorgan Chase Credit card department,

Balance transfer fee Missouri

I transferred - credit card balances totaling $660.00 to Chase at a promotional 0 % APR for 12 months. At the time my bill was due I paid my card in full less the balance that was under 0 % promotion. I was subsequently charged an interest fee event though I paid the full balance that was subject to interest charges.