Debit of extra EMIs from my Bank account

Location/place: Gurgaon

Name of company/service: Bajaj finance

I had purchased TV and IFB washing machine from DAWAR Electronics Gurgaon which was financed by Bajaj finance.After payments of regular EMIs for some months Bajaj Finance withdrew the amount of EMI twice a month without any initimation to me.Over and above even after copletion of the EMI tenure they continued to withdraw the emi from my account in the next month.On sevral complaint and written clarifications to bajaj finance they are reluctant to refund the extra amount back to me.