Ansal Api Infrastructure — non delivery of promised flat in paradise diamond 2

Address:

Lucknow, Uttar Pradesh

I had booked a flat in paradise diamond 2 sushant golf city, ansals api in 2010 and has paid periodical instalments for some time. However inspite of frequent inquiries and personal contact the builder has not given any reason of delay in construction or handing over of flats till date. Even i had requested for refund and have deposited necessary documents more than six months back to the company but no action has been taken by the company till date.
Uprera number for the project is also not available to lodge the complaint with rera.
Kindly help and advice.