Get your money back or beat that sales person to a pulp...or maybe do both. I can't believe that someone would make up such a crazy lie. The worst a dealer salesperson has told me was that some car was a sport edition when it wasn't. I quickly checked his ass and he rephrased it by saying he, "thought the car looked sporty."
If it is a legitimate dealer you should get your money back and work your way into a great deal on another car. I would recommend you get a lawyer involved. The best financial deals usually involve a good scare from a official letter.
If it is just some random used car lot, I would def. get my money back and take my business elsewhere. I don't trust little used car lots, let alone ones that have a history of lies.
Get a cheap SVT on ebay!