Inles you syned a paper saying no refundable then you can get your money back. It's real easy if you used a credit card but cash or check would make it almost impossible to get it back good luck.
Even if he signed an agreement, it cannot be perpetual. It must have a set delivery date on the contract and if the dealer goes beyond that date, they are in breach of the contract.
If they don't have a contract or the contract doesn't have a clear delivery timeline, the consumer will always prevail.
I would review the contract and if you are entitled to a refund, I would tell them your state's consumer division and/or your lawyer will be contacting them shortly unless they make that deposit refundable at this point.
Don't get the deposit back just yet, just get the deposit refundable in writing then go start looking elsewhere to see if you can find something else.