Consumer Redressal

Hi I have booked a flat with Dreamz Infra. It was booked on May 2012 and as per MOU the possionn will be after 18 months plus 2 months exception. so it comes total 20 months. As per their new Sales Agreement, the possession will be by 2015. The sales agreement was done in Feb possession is changed, they said we have applied for BBMP approval and it will take another 18-20 months to compelete. We were informed by their legal department that other approvals are already taken. But till date they dont have any BBMP and DC approval and whenever we call them, they say it will be done in next 2 months but we dont see any progress. If we cancle the FLAT now, there is no benefit for us after wasting this much time. They are asking to cancle if you want. I am looking for compensation as they have just cheated us for this long time. they just collected money from us and now asking us to cancle if we want. Please suggest what I can do from here.