Builder not refunding

I have booked a shop in Regal Emporia Project in Noida. I am a doctor by profession. Regal came up with a concept of ‘Doctor Floor’ in their commercial complex. Doctor floor was designed to be located on 5th floor of the commercial building. I booked the shop in this project in April 2013. I made payment for booking amount which 10% of the shop price. Another 10% of payment was made in June 2013, which was due in 60 days from booking. A total of close to 10 lakhs were paid. For next two years there was no communication from the builder. In May 2015, we received a letter that doctor floor has been relocated to another floor (at much higher floor than originally booked 5th floor). Builder asked me, if we want to be relocated at floor which is at much higher elevation. The response was sent immediately to the builder stating that I am not interested in relocating my original booked unit to a different floor. Therefore, it was requested to refund the money paid along with interest. After that we called multiple time, visited their office multiple times, sent multiple e-mails requesting refund. However, till date builder has only made hollow promises to pay my money back. I request you to please help us with this. Also, to note that I am not the only one who has been treated like this. I know other people who also going through same issue. Let me know, if any documents, e-mail etc are required. I’ll be more than happy to share any supporting documents. Thanks in advance for your help. Regards, Dr. M Hasan