Kotak Mahindra Bank — Credit cards fraud. Kotak does not honor reversal letter

Address:

Mumbai

I have a credit card and I had a balance of 25k to pay. I requested the bank to give me an option to pay in parts due to Covid situation. Bank sent me a letter saying that I could pay 4250 in 6 instalments and this would clear balance with no dues. However, now they tell me that I hv to pay interest on the amounts. I paid up 35 k already and they still tell me I have to pay more.
The call centre staff are apathetic. The collection people are totally not reachable. I have lodged a complaint with RBI. Totally frustrated and feeling cheated by Kotak. After serveral escalation mails, no action from their side.
Worse customer service.
They have cheated me. I will fight for justice.