Mantri Developers — Delay in handing over Flat/ No response from the CRM.

I have booked my 2 bhk flat in Mantri Webcity project, Parcel-2, tower-H in year 2015 October and the possession date was October 2018 that is after 36 months. But so far I didn’t get the possession. When I visited the site the parcel-2 work was completely stopped. I can see only the tower structure is built.
The CRMs are not giving any reply to mails and no one is receiving the calls. Every time I tried to send the mail, it bounces back showing the mail recepten does not exist.
This is my hard earned money which I spent on a project expecting returns from it, but it’s in vain.
Your kind and urgent help is needed. Otherwise I have to go for a legal actions.