Consumer Redressal

I had booked 1 BHK flat on Feb 2014 in Adani Shantigram on SG road Ahmedabad in a subvention scheme 15:85. I have been told by their marketing agent that after down payment of 15%, no payment is required till 24 months or possession date (whichever comes first). I do not have possession date confirmed by builder and before 24 months of subvention period end, I got email from bank to start paying PEMI effective May-2015 that gave only 15 months of subvention period. The PEMI interest till Jan 2015 was paid by the developers , and then after they have stopped paying the PEMi. Bank has already started recovering PEMI from my linked bank account. Please suggest what can be done here to recover PEMI of complete 24 months of subvention duration.