Income tax challan entry made by bank is incorect

Hello concern I have made payment of incometax challan for A.Y 2016-17 on 21/03/2016 but The Banker has entered in system A.Y. 2015-16. Neither i focused on it nor banker Now the damand has been issued by IT dept. for payment of tax I don't know what to do do know since its being reflected in 26 AS of A.y 2015-16 and i have not claimed in A.Y. 2015-16 ITR