[CT] dealership forged documentation

Good evening, I’m currently dealing with a large dealership, that ive had dealt with problems after I bought my vehicle. Last year when I bought the vehicle I left the dealership and they had forgot to tighten the lug nuts and me and the vehicle went down the side of the highway riding on a rotor, and was able to get a tow truck to come bring the truck back to the dealership who apologized and offered me one free oil and to fix the problems and said sorry, I was able to get them to throw in a few accessories for the vehicle but ultimately just wanted to be done with the dealership instead of trying to bring it further (looking back now I should’ve tried going further). So now we have today’s issue of me being told that I have canceled a warranty on my vehicle as of September last year (2 months after buying the vehicle) and was given a refund on the warranty, 1. I would’ve never cancel a factory warranty that I paid 4000$ for. 2. If I did cancel the warranty that doesn’t explain where the 4000$ went. I called the dealer and asked them to send me the document that I signed and the manger told me that I went down and signed it in person back in September, so anyways I ask for the copy and he sends it to me this is the craziest part, on the cancellation form they crossed out another persons first name added my name changed letters around in the middle and last name to make it look like my name which they spelt wrong, crossed out the vin and put my vin, the address on it Isn’t my address its The person on the orginal documents who they forged my name over. I was able to do digging and find the persons who’s paperwork they were forging my name on and he called me and and confirmed that, that was indeed his signature and that they completely wrote over his name and that it was in fact all of his old vehicle information. To summarize everything I have no warranty on this vehicle and I’m now missing 4000$ with no refund, on a paper I never signed that was obviously forged that I can’t believe they even sent me. I’m looking for advice on what to do cause I don’t know if I should be lawyering up or if it’s something I have to fight the dealer about all over again. But I’d imagine that them forging my name onto another persons document has got to have something going for it right?Let me know what you guys think I should do I’m at a loss and plan on just trying to go down and talk to the dealership but don’t want to make the wrong decision.