I don't know your circumstances at all. But for every one like you with a genuine issue that you can't go through, the dealer probably hears 5 lies. That's why the contract - it spells out exactly what happens and how money changes hands.
I'm still struggling with how money is due back. The contract stated deposits are not refundable. You didn't go through with the contract. There is no reason to expect your $$ back. Sure, they could be nice and give you the $$ back but are under no obligation to. And you shouldn't be upset that you lost the $$. It's probably better than being in bind by purchasing the RV.