Form 10e and itr submitted u/s 89 relief but got tax demand u/s 143

Dear CAs, I received a arrears income for FY 2014-15,15-16 in FY 2017-18. Prepared online the form 10 E and submitted as AY 2018-19 successfully got the e-Filing Acknowledgement Number also. Filled the ITR for AY 2018-19 and claimed relief u/s 89 , final amount was a refund. Now ITR has been processed ,got a INTIMATION U/S 143(1) for additional tax demand. In "As Computed Under Section 143(1)" it clearly shows 0 relief u/s 89. Please suggest what should do here. Also when trying to file rectification AY 2018-19 is not available in dropdown.