God thats horrible mate, I echo everything that has been said.
But also because you bought it from a dealer, you really should have some real compensation your way. They sold you a stolen car, they will have advertised it as HPI checked etc etc, so I am very sure you are pretty well covered in that department.
I would make a flask of tea, pack a lunchbox and trot off to the dealership sit down and tell them you are not moving until you get a FULL REFUND for the car, plus 10% off the purchase of another to cover your expenses and ordeal you had to go through. Write to head office at the same time explaining everything