What mostlikely happened is that some offered a lot more money over the sticker price. So that the customer would get his car sooner. Did you sign any paperwork, and give them money? If you did it is called a contract. And it is binding in most states. Was thier a delivery date stated on the contract? If so they will of missed the delivery date. And can be in breach of contract if they fail to deliver the car. Now if they do not receive the car because of Toyota, it's not thier fault. In your case because they sold the car out from under you they may be considered in breach of contract.
Make sure that they did actually sell the car to some one else.
Contact Toyota and see if it was your order that they sold.
A giveaway would be if you receaved a second prius key chain in the mail.
I got mine about 35 days after my order was placed.
Toyota can place a lot of pressure on the dealership. If this fails.
:twisted: I would next report them to the Better Business Bureau for starters.

Next would be to talk to any local automotive delealership sellers organization. They may have a sticker in window at the dealership showing what organization they do belong too. Oh expect a phone call from the dealership with in seven days after doing one or both of these things. You should notice a tone of concern in the sound of thier voice when they do call.
:roll: The last choice would to contact a lawer to see if thier is any legal pressure you could apply to the dealership. This is a last resort. The only way to even consider this rout would be to be able to prove it in court. If you have something writing that will hold up in court. Before you go down this path calculate the cost, and the chances of winning. It may not be worth-it.