SBI — wrong rc and interest charges

Address:

Sector 12 Noida

I have deposited all 30 emi of car loan as per si. Now when it is time to close they are saying balance is left as i did not submit rc on time and charged me 11800 rs in total for 3 months. Also some interest charges. Loan person is good for nothing and does not know anything how to deal with customer and bm shows a pity exercise that nothing can be done. Where should i complaint of these cheats?