RBL Bank — I am complaining about credit card fraud.

Dear sir,

I am using RBL Bank credit card associated with ET money. I have widthdrawn RS 5000 from my credit limit which is due on 10/09/2018. I have paid the sum of RS 5000 on 03/09/2018 but RBL has converted the amount into EMI without my approval. When I received the mag I talked with the Et money customer care they said that this was a internal problem and you don't worry you have to only pay the 5000 . But now the RBL bank has charged me the amount of RS 662 as they are saying that it is the processing fee for converting your amount into EMI.
They can show me no proof for the same. They said you have converted your amount in EmI through IMPS. How strange is that. Please help

Chetan sehgal