Agreement of sale - Rectification of gift deed

Agreement of sale - Rectification Deed I have entered into an agreement for purchase of a house. It was gifted by the donor(Father) to the present seller(Son). When I approached bank for loan the panel advocate observed that while making the gift deed schedule of the property is mentioned as Plot No: 1 instead of Plot no: 1, Plot No: 2 part. They told me to submit the rectification deed for the mistakes, otherwise they can't sanction me loan. But the seller is saying that his father can't come as he was missing since 2016 and his whereabouts are unknown. He has two sisters also. The Seller is not returning the money I've given to him nor he is doing the rectification deed. What should I do in this situation? What are the options I have in this situation. Whether the expiry of agreement of sale will have any effect on me? Please guide me about the options I have. Thanks in advance