Excess amount of Rs 39,791/- deducted by HDFC Car loan Dept.

This is regarding HDFC Car loan installment . Bank is deducting excess amount every month. and we are feeling major harrasament by bank again and again. Our car loan a/c no. 27975407 AGN CRV HONDA CH-01-4060. Please solve the matter asap. We have requested so many time to refund xcess money but no body is responding to us.