[Resolved]  HDFC Bank — Converted a credit card withdrawal into an EMI without approval

I had withdrawn 10, 000rs through paytm through my HDFC credit card ( due to hardship and I always pay off my credit card bills on time) . I have paid full outstanding for every month however I see my credit card statement and realize the bank has converted the 10k charge into an EMI without informing me and is earning an interest rate of 20% without MY authorization.