Consumer Redressal

I bought a flat with Ireo Rise in Mohali with subvention scheme , thinking will sell it on possession . being L&T builder delay was not expected. I took heavy loan from HDFC.. But i didnt realize that subvention is not till possession but till 30 months and after that EMI started. Possession is delayed. As on date its 15 months late.i disbursed one payment and didnt disbused more. Ireo sending me demand notes and threats to cancel. I am demanding from them to let me know the expected date of possession and reason of delay, which they not telling. For new customers they offered 40% now 60% on possession, i told to transfer me under same scheme, they refused. Now they given me strong letter to disburse dues with intrest , else threatned to cancel the deal, without telling me anything on possession plan. Its expected to be delayed more by 12 months as per informal news. How can you help? Can they cancle it? I am intrested to linger it on as dont want to give more EMI.