Milage charge?

I bought a car from a dealership and 2 weeks later they called to say they could not get financing and i had to bring it back and get something else. They had nothing else that i liked and when i asked for my down payment back they said the were charging me milage to the tune of $450. Is this legal?

Yes it is. Who is suppose to pay the wear and tear you put on the vehicle for those 2 weeks?