Paytm Mobile Solutions — Paytm postpaid fine

Im Hitesh L. My registered phone number is [protected]. I had used 400rs from paytm postpaid, I had lost my sim which was my registered in my dad's name. So it 8-9 month approximately to pay back. But the loan amount with fine was Rs. 5255 which I paid after several attempts of trying to get in touch with the customer support. But never got a response it is unethical to put up a fine that's 15x the amount I used. I need them to pay me back the excess money that they had taken from me.