Supertech — delay in possession-hill town sohna road

I had booked a flat in hill town project located in sohna road for which due date of possession was dec 2018. I have not yet got possession as the construction has been severely delayed/stopped midway. I tried reaching out to supertech but they are not even responding to my emails and calls. I want to register a complaint against supertech for duping me of my money and needa refund for the amount deposited aling with interest as soon as possible.