Signature forged on auto lease - need help

In February I found out (from the finance company) that the NY Lexus dealer I leased my car from submitted a forged lease agreement that was different from the one I signed. The difference was in the retail price (higher) of the vehicle and in the residual value (higher) of the vehicle. As far as I know, this did not alter my lease payments. However, I was unable to buy the vehicle at the end of the lease because of the difference in the residual value. I have a copy of the forged lease agreement from the finance company and the customer copy of the lease agreement that I did sign. I've made the finance company aware of the forgery and I've contacted the dealer - of course, the dealer has not responded to any of my messages.

As the victim, how do I go about bringing the dealer to justice? Do I call the police on them, do I call the Westchester Co. DA or do I call the Atty. General of NY? Also, would I be able to sue for damages on the forgery alone? Any help would be greatly appreciated. Thanks