Dear Amrita Prasad,
At the outset, let me clarify that this site is designed by a group of senior Banking Professionals to assist Bank Customers at large to provide guidance for resolution of any complain/query/grievance in respect of financial services. This site does not belong to any Bank or a regulator, which may please be noted.
If my understanding is correct, what you have attempted to state is that your bank erroneously linked your ATM card with another customer's account. You have withdrawn money from that account. In order to satisfy the victim customer, your bank is demanding the money you had withdrawn.
In this connection, the the following aspects come into play
1. I have difficulty in believing your claim that the bank could have linked your ATM card to another account. My surmise is that you had received ATM card of some other customer and also the related PIN. You have taken advantage and withdrawn funds which did not belong to you.
2. I see a possibility of the victim customer's failure to intimate change of his address to the bank. Due to this, his ATM card got delivered to you at the address. You have taken advantage of the situation. If this is correct, you have not been fair to the bank or the victim customer. In the above scenario, notwithstanding that you did not invite the problem, you are under moral obligation to refund the amount you had withdrawn.
3. Your dispute that you did not withdraw the amount being claimed by your bank or the amount debited to your account to compensate the victim is a different matter.
4. Your bank cannot escape responsibility for the mess up. The bank cannot refuse to accept your complaint. I suggest you to send a complaint through email or letter, directly to Nodal Officer of the bank. In case the Nodal Officer fails to respond or resolve the issues within 15 days you may write to the Banking Ombudsman for resolution.
Contact details of Nodal Officer can be found on the bank's website. For address of the Office of the Banking Ombudsman, Area of Operation (jurisdiction) and the procedure for lodging complaint, you may access the website https://bankingombudsman.rbi.org.in/
Regards
J R Mohandas