DMI finance - Reckless amount charging

I was taken a loan from mobikwik under dmi financial gateway. I have paid my emis in proper time and some emis were paid pre-time but it was not updated.with in some emis and in other emis the auto debit did not happen and even I paid through the pay now option but the amount paid was returned back with the statment transaction unsuccessful and amount was refunded as per thier or my bank norms.And the other concern was I thought to pay for the second time where there was no option for paying it second time and now they were charging me for late payment which was all the whole drama played by them which I feel. And coming to the last point some amount of **** change was shown as the balance amount for loan closure which even was paid but no update in the system and which in turn daily recieving the calls and mails regarding the balance payment and mentioning that It might impact my credit score.even I tried to contacting them through mail and call support which helped me no where.