TDS paid without purchase of property - Income Tax

Hello, When a sale deed was not executed yet the potential buyer paid TDS on entire consideration of the agreement, the onus to prove that sale did not take place shall lie on the department or the assessee ? The assessee has made every possible document available to prove that sale did not take place. This transaction was not reported in SFT either as required u/s 258BA of the Act. Since the seller is non-cooperative and has not even returned the amount paid as advance, confirmation from the seller is hard to obtain. Thanks