1. How much amount you had taken as loan and did you repay the amount in cash?
2. Have you not taken any receipt for having deposited the said amount to HDFC through its collection agent?
3. If no, then you have no evidence of your said repayment which you should have collected and preserved,
4.In absence of any evidence that you have paid back the loan you had availed from HDFC, it will be proved that you still owe the Bank the said amount,
5. If you are no more an Indian Citizen then the Bank shall have to initiate action against you through Ministry of External Affairs and approach the US Govt. for collecting back the outstanding amount,
6. However, your parents in India can lodge a police complaint against the Bank for harassing them for your act.