Seeking refund and damages

I booked a unit in Jaypee Greens, Noida in August 2012. The flat was booked under the subvention scheme, in which I paid approx. 15% of price as down payment and took a bank loan to finance 80% of the price. Subvention scheme is different from a traditional construction-linked plan in a way that although 95% (80+15) of the price is paid immediately to the builder, EMIs start only after 2 years, which in my case happened in September 2014. As per the PAL, the builder promised to deliver the flat within 42 months which would end in March, 2016. However, looking at the construction progress (the building is supposed to be 38 floors tall and till now, they have only constructed a raw structure of 19-20 floors), it seemed impossible that they would meet the target possession date. Further, when I raised this point to the customer care team, they very conveniently told me that possession date has moved to December 2017 (I have a copy of that e-mail for records). I'm pretty confident that with this speed, they will not be able to complete the project even by Dec, 2017. I also asked them to provide me a Builder Buyer Agreement, which has been made a mandatory requirement under the UP Apartment Act, 2010. But they have bluntly refused to issue it (I have all the e-mails where they refused to provide the agreement). As you'll appreciate that I am now paying EMIs on 95% of the price of the flat, with no sight of when will I get the possession. Ideally, I would like to cancel the flat and have Jaypee refund all the money that I have paid till date but I'm not sure what legal recourse I have. Please advise.