Personal Loan Paid over what i have taken still Bank asking me pa

Dear Sir/Madam, Need your advise ! In 2011 I got a call from bank stating your name is selected for Pre approved " CROSS SELL PERSONAL LOAN " of 57k for 36 months .. Executive did not give complete details and asked for the confirmation over the phone and credited the amount of my account. It was auto EMI and it was getting deducted my account every month of Rs 2533/- .. I released after 30 months that I am paying 33.58% and paid overall Rs 75990/- and Bank is asking me to pay additional 6 months EMI as well which will be Rs 15318/- . I stopped paying amount and i requested bank for settlement and i agreed to pay additional amount of 2 to 3k.. But Bank is not willing for it and they are asking me to pay 10k .. Today I got a call from bank lawyer, explaining the rules and regulation and even he offered me that he can help in getting the settlement of 10k, if no then i will send the legal notice, I asked him to send the legal notice and ended the discussion. Pls advise whether I have done anything thing wrong or you advise me to pay 6 months EMI and close it ? or pay 2 to 3 k and close it ? .. Since i already paid additional of 19k so not planning to pay any additional to them.. Very important, out of 57000/- Bank credited only 53000, remaining they have taken for insurance and processing free etc .. His RBI rules allows for 33.58% ?