Can a dealership sell a finance car with bad tires and bad timing belt?

i purchased a used car from toyota the first car they sold me when i took the car home it was making a funny sound so i call them the next day they said there's nothing they can do they will not put any money into repairing the car so i took it back anyway and left it there.I received a call that wednesday saying that the struts and the struts mounts was bad but they still was not going to repair the car.ok they took the down payment of 4300 hundred dollars and used it on another car a 2005 honda accord v6 i took the car home couple days later i started to hear a sound that did not sound right so i took the car to the shop i was told the tires needs to change one of them has a cut on the tire so that 3 tires that needs to be change and a timing belt this is a car i have to pay for,for 4 years now they are also saying that there was a paper i did not sign this paper needs to be sign in order for the bank to approve the car loan.they already told me it was approve thats why they let me leave with the car now i tried to give them back the car but they are telling me i can't get back my down payment of 4300 hundred dollars and they would'nt even change the tires a big dealership like toyota be aware they are selling bad cars.