Deepika Estate/ Aarush Motors And Others — money taken for car name transfer, job not done, money not returned

Address:

Kolkata, West Bengal, 700041

I bought a 2nd hand car i10 from an agency - deepika estate, kolkata also known as aarush motors. They completed the transaction, handed me over the car and all documents, and got my insurance done.
After this i applied through one of their sub-agents for car name transfer into my name, in august 2017. I paid the full amount in advance, rs 16000 and waited for the name transfer. The transfer was said to take anywhere between 30-45 days because it involved rto change (Alipore to beltala rto). Till date there has been no progress on the matter. I have not received a single proof of my papers having been submitted into the rto or no proof of a money receipt has also been given. They have been assuring me in various way but no progress has been seen.
Finally i asked for a refund, which they agreed to pay by dec 1st, 2017. But till date neither the refund nor the papers have been returned to me.
I want at least the money to be returned, in ideal case i want the papers back as well so that i can re-submit through someone else.