Refund on cancellation of sale agreement.

I booked a ready to occupy flat in bangalore in November 2013, and signed the sale agreement in March 2014 by doing a payment of Rs 10,00,000. We planned to go for bank loan to fund the 80% of the flat value. In June 2014 the article came in Newspaper that the Sanction plan/approval on the project was withdraw by the authorities. I immediately got in touch with the builder for better u derstanding. I got to know that the buder had encroached the part of government land that was allotted for dalits and public library. The issue was from I think 2010 this finally culminated to withdrawal of approval of building plan in 2014. The builders ask me to wait for 3 months so they could get the case to an end and also mentioned that the registration have been stoped. l requeste for case details and updates. The builder would not provide any details nor any status and asks to wait further. Suddenly I got a call from builder in november 2014 asking to register or cancel the apartment. On checking bank informed that without any legal clearance documents from the builder, they will not fund the project. Finally. We decided to cancel the booking in end november 2014 for the reason 1. No clear title as property was in litigation 2. Bank was not ready to fund the project We sent mail to canel the agreement and refund the amount. Note. We sent 5 -8 mails. But they never replied to any of the mail including the cancellation request. now its 1year since we did our sale agreement. The property is still in litigation. And its 5 months from the date we sent our cancellation request. I request your help, in how to proceed with this issue and get the refund of Rs 10,00,000 .