Jaypee Infratech — Refund against buddh circuit studio phase 1

Address: Gautam Buddh Nagar, Uttar Pradesh, 208002

I had book a studio apartment in Buddha circuit phase 1 in April 2013 and paid about 8 lac till Aug-2013. Since then there is no response from their side.
On contacting no. Of times they have send me a email for refunding the money along with 12% interest till the date of payment and total time frame for refund would be 15 months.
I have submitted the required documents in April 2017 and waiting.