Reserve Bank Of India (RBI) — credit card

myself rudra nath dutt credit card holder of hdfc bank would like to complain against credit card extra interest charge.last one month stop the payment and ask them to clarify me for the charge of interest but they say you have to continue your payment your complain is different issue. i told them through mail you ask for the payment but they refused it. now a days the force me for the payment without any clarification. please help me to give proper guideline my mobile number is [protected].and my email id is- [protected]@rediffmail.com .