Ansal Api Infrastructure — non-possession of, flat booked in 2011

Address:

Gautam Buddh Nagar, Uttar Pradesh

It has been 7 years since i bought a flat in sushant serene of andal api project in greater noida. I was promised to be delieverd in sept 2014. Today we are standing at april 2018 with no sign of delievery. Our flat is in t12b. On contacting ansal infound iut the customer number never works, the mentikned email is now blocked and i need a direction on how to approach this issue now. I wish to collect all home owners who are in this propert and let us sue this company for ruining our lives. We have given almost all the instalments except the last one which was on possession. Please let me know how to get my money with intrest.