Notice u/s 143(1) of it

In my on line return filed for AY 2015-16 I claimed Rs 35348/ as rebate in Income tax by splitting the 6th pay Commission Arrears for FY 2007-08 & 2008-09 received in Fy 2014-15 U/S 89.But the CPC Banglore issued me notice U/S 143(1) asking me to deposit the Rs 35348/ as they did not accept my claim U/S 89 of splitting the arrears.Was I incorrect U/S 89 by splitting the the arrears as explained above?If not what action should I take for remedy of this action of IT Dept. Thanks & Regards Krishna Kant