An assessee had included Rs.50000 as income in F.Y.2019-20 but the TDS against the same had been taken into account in F.Y.2020-21. He has claimed TDS deduction for the same in ITR in F.Y. 2020-21. But the same has been disallowed by the department. The department has demanded for the same amount of tax. Is there any way to deal with the same?