Mercedes-Benz of McKinney

Sales lied and manager is hiding! I bought a Porsche just over a month ago from Mercedes Benz of McKinney under the impression that the vehicle had no current or pre-existing problems or conditions. I was assured that there were none and under that promise I purchased the vehicle. Within 2 days of buying the vehicle it was not driveable. A barely got the car back to the Porsche repair center. Upon dropping the car off I was told that there would be over $10k worth of diagnostic testing required to "hopefully" identify the problem and then another $5-7k in repairs. When I reported this to Mercedes I found out that that there WERE prior issues with the car including a ruined transfer case and rats chewing the wires. I was never told this and would not have purchased the vehicle if I had known. The General Manager of Mercedes of McKinney has been extremely unprofessional and unhelpful. He refused to return any phone calls and I didn't get to talk to him until I drove the 2 hours back to the dealership. While I was there he just fed me a bunch of bs and promised to help and call me back. The car has been in the repair shop for almost a month now and after almost two dozen calls from myself and from Porsche, the GM of Mercedes has not responded once. I believe he is avoiding responsibility because he knows that he lied and screwed me over with a bad vehicle that was broken. I haven't been able to deal with this face to face because I travel for work but I am trying to resolve this. I want them to take the car back since I bought under false pretense and I believe it to be completely unethical. I have asked this since the beginning but I just keep getting the run around! I would encourage everyone to think twice about doing business here. General manager is irresponsible and negligent. Make this right. Take the car back.