Standard Chartered — Bank charging me heavy bills even after returning their product back

Address:

Pune, Maharashtra

Bank sold me the merchandise offer which include holiday package, it was of rs 4300/- which i taken on installments after few installments I feel to repay full amount at one go for that I contacted Bank and the salesman who sold me that package. However because of miscommunication from bank and salesman I never get reply from them.
This keep increasing my late fee charges, for that I also registered the complaint with bank however that also got miscommunicated and my bill goes on increasing. Finally I sent their package with registered post back to the bank to discontinue relations with bank in the month of may. However till date bank keep charging me their fees and my bill now goes to rs 11299/- from credit card statement my real amount is just of 2500/- (nearly).
I keep contacting with bank now they say it is fault of person who sold me the product.
Please help me as bank has sent my name to CIBIL.
Kindly contact me on[protected] for more details.