Lawyer threatening to sue for credit card fraud

10 years ago Someone scammed my credit card pin and bought multiple rail tickets worth 50k from Delhi to different cities and recharged with his number. I filed a fraud case few months later.(6-7 months) Banks used to call often for last ten years to pay up. There were lots of cases over the years but they couldn't do anything . Now some lawyer is threatening to sue me to Delhi high court if not settled for 15k over phone. Should I settle for 15k ( flight would cost me more to travel to Delhi incase he files) . Will he not ask more later? Or I should let him file. I think I will win coz they got no proof and my payments are always paid on time and I don't travel to that city where fraud bought tickets, I have alibi etc. In short I have enough evidence. But if I don't get reimbursed for harrasment over 10 years then I think it's not worth wasting my time and energy. I. E can I sue the bank and expect to get anything ? What do you suggest I do?