Technically, there is nothing you can do, but complain to them and start doing business elsewhere. I would not expect to recieve any kind of refund. They set a price and you paid it. There is no way possible that you can prove that you did not get the dirt on the wheels and fuel in it after you got it home. Their word against yours. Chalk it up as a learning experience and enjoy your new plane. Next time shop around for the best price. Was not trying to sound harsh. Just laying out some cold hard facts.