Mentally Harassment & Charging excess money

Dear Sir/Madam I totally disturb from the services of SBI credit card department. I used a card for which on call /mailled i settled it in Nov-17 in 80000/- rupees in 6 installment of 13333/- each for which i received a letter on mail. when i paid first installment still received call from SBI, for outstanding balance payment as per statement for which i complained to costumer care aswell mailed, again i paid second but calls not stopped again mailed and inform to the guyes who called me for payment. I again paid 3,4,5th but regularly received call. In Apr 18 Before the last installment in due date i mailed to sbi credit card department to update my settlement, where some doubt in my mind they didnt reply for that mail and due date lapse. They again called me for payment for last installment and said your settlement will be closed after the payment.I paid it and when i asked for NOC they said that your settlement is broken due to late payment of installment which is only 10-15 days delayed only because of their unwanted calls and non updation of settlements/ misguidance and not reply of last mail before due date. And after that their executive calls me and using unethical languages/abusing languages about me & my family for which i also complained through mailed calls and visited at their office Jantar mantar and Netaji Subhash Palace. but no solution. On call of their executive i visited at Netaji Subhash Palace Branch neither he met me nor his boss, the third person met me and assured that your case is genuine and it will be resolved. After many followup, calls, messages after 3-4 months he replyed that it could not be resolved you have to pay the amount or settled it again. Many calls received by me after that one executive again used abusing language from his personal no. for which i also complained to costumer care mail id with his call recording of their abusing languages on 7th Aug,but they just registered the complained on 13th Aug 19 till they didnt reply from last two years the are doing like that and increasing balance amount. The delay in payment due to missguidance/misscommunication and nature of cheating to earn money i have no intension not to pay the money on time. I paid their Rs 80000/-. One of the movement I left my job due to this, and after the confirmation i joned again but no solution. I am requesting you please give the best suggestion to come out from that i getting pain from their services but due to government bank they are free to say anything and not closing the settlement.