Can car dealership take my car back after 2 months because the financing didn't go through? And keep my down?

I purchased a used car from Doral GMC in Miami FL after 2 months they called me and are demanding that I return the car because financing company cancelled supporting the loan I made my first month payment on time and everything. I put a down payment of 2200 and they are saying they will not give it back I told them they can have the car if I can get my money, the financing company sent me a welcome letter in the mail and everything it has been 2 months I know I have to give back the car but can they take my down payment of $2200 I have reported them to gmc head quarters, the attorney general of Florida and bureau of mv complaint division against dealerships. I'm ready to go over there and see what they can do either find me appropriate financing or refund me 2200 down payment and they can have the car, the crooks at that dealership DORAL GMC are liars and are weasels and they need to be exposed for their deceptiveness and being unfair to customers in Florida there is a law against deceptive trade. Please anyone know how and if I can get my 2200 back I heard they may try to charge me for mileage, I put 4,500+ miles on the car thus far please help.