Avj Heights — refusing to give possession

Address:

Gautam Buddh Nagar, Uttar Pradesh

I own flat # d 307, at avj heights, plot number 12/2, sector — zeta -1, greater noida. I paid all amount in 2014, and asking for possession since 2015, and they kept saying couple more months, but now when i call a guy named karan tell me every time that builder is in jail and nothing can be done until he comes out of jail. What should i do? I also have been told that he has sold my flat to some body named preeti khanna. I am completely lost and distressed about this. Please contact me on my email - [protected]@yahoo.com