Cheque Fraud and 420 (Criminal intent to loot and Fraud me for jewelery)

Hello I am a private firm employee, who does jewelry deals on the side on commission basis, recently a dealer approached me and asked me to help them sell polki diamonds, we approached a former Gems dealer who did fraud with me by saying that he would help me sell these diamonds, he took me to a showroom went inside with my goods all alone, while i was waiting in the lobby, the gem dealer came out said the deal was done and handed me a cheque as a payment for the sale done and kept the diamonds for himself - this cheque was from his account and he faked the signature of the showroom owner on the cheque. He gave us a post dated cheque 15-18 days from the deal and later then I realized that he had pawned off our jewelry and gambled with the money he received - when approached he openly challenged us that we would never get back our diamonds and also directly went to the police station and tried to lodge a case on us for harassment, luckily after telling MY story at the PS they did not file a complaint from the gem dealer as he also had criminal history.