The first thing to do is get the vehicle inspected by a certified appraiser. If the body work is obvious then the dealership probably knew about the damage before it sold it to you. If that is the case ask them for your money back and Gove them the car I'd they refuse, you need a lawyer.
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You need to start "building" your case now, via writings. Phone calls will not do at all. Call a good consumer protection attorney in TX for advice on how to make this work against dealer, found here:
Dana Karni, Amy Kleinpeter and Sharon Campbell come to mind as top attorneys in TX for this area of law. Feel free to say hello for me.