Delayed Construction of Flat but still some time in date of possession

Booked a flat in G Noida in July 2015, builder has mentioned November 2017 date of possession. Project started in mid of 2014. The over all completion is only 25% and since one year only 5% work happen on the site. I do not see any hope for project to complete on time, as build is out of cash flow and he is not getting any fund from Banks. Although in BBA, there is a clause that if I surrender the property after completion of 12 months of registration, builder is liable to refund me the amount with 12% interest, but since he is running short of funds how will he refund and how can law help me