HDFC Credit card dept still issuing invalid due statements

Dear Sir, I had taken credit card loan of INR 22,500 from HDFC credit card on June 2013, with repayment tenure of 2 years and monthly EMI of 1,040 Rs. later the EMI was revised to 1,070 Rs may be because of change in the interest rate, if i'm not wrong. Since I missed EMI some months have paid late fee and interest charges some times in the tenure. During the end of my loan EMIs of around June 2014 got 3100+ Rs as I missed just a single EMI. I denied to make payment as Interest they were charged was too much and asked for justification on too much of interest had been charged. People from bank started called me to ask for making payment, I asked why my EMI dues are too much, when monthly EMI is just 1060 Rs, No justification was given !! as they used to tell since your outstanding is this much you should make payment immediately. Next month amount grown to 5270 !! This is what made me not to make payment until clear justification would be given on why amount grown too much just for missing EMIs two months !!! Later in the month of September when amount credited to my account without my knowledge they deducted 7800+ this was the total outstanding !! leaving ZERO behind in my account.. Story has not stopped here.. Even after they got total outstanding amount they again started sending Outstanding e-statements everymonth, really don't know on what basis they doing this !! Now my total outstanding is again comes to 7200 Rs as of May 2015. Please suggest me on how to go about this !!