I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear about your dilemma.
There is unfortunately no legal right to cancel a sales contract for a new car unless the agreement itself says so. A dealership will sometimes work with a customer to put them into a different vehicle if they're not happy with the one they chose, but the law doesn't say you can simply cancel the deal, take your original car back, and walk away. Read your contract carefully to see if it gives you any sort of "cooling off" period. I've never seen one that does, but it is possible. If it doesn't, you can try to negotiate with the dealership to cancel the deal, but they can sue you for the profit they would have made on the sale had you gone through with it. And that means canceling could mean you wind up paying for a car you don't have.
Since they only agreed to cancel the first contract based on your agreement to enter the second, that's the one they could sue you on if you walked away. However, you should be able to purchase either car, as long as they still have both. I'm afraid you wouldn't be able to take your old car and walk away without buying anything.
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