You can try it: now you take the original ID card to the credit department of the bank to explain the situation. It would be more convenient if the handlers were still there. I think as long as you pay back the money owed by your relatives to the bank, the bank can go through the formalities for you, and you can go to the lobby of the construction Committee to go through the mortgage registration cancellation with the house book and repayment certificate.
For reference, good luck ~ ~