Steel Seal repair done without written permission?

Me and my girlfriend bought a 1993 Ford Explorer from Breeze Motors on 11/08/10. The vehicle was sold to us by David Franciosi. He asked us what kind of car we where looking for. We told him something around $2000 with low miles. He showed us one vehicle with around 180,000 miles on it and in our price range, we said that the mileage was way to high for what we where looking for. He then showed us the 1993 Ford Explorer which read on the windshield: $2800 4x4 Low Mileage. He began telling us that he just received this vehicle a few days ago and that "it had only 93,215 original miles on it." We told him that is pretty good for being such an older car. He told us that it had only "one previous owner and it wasn't used much." We told him that we only came with $2000 cash, which then he proceeded to tell us that he would take $800 off because he knew we where tight on money. He said to us "With 93,215 original miles on this car you could drive it for a year or two and still get $1500, when you sell it." After less than three weeks of ownership of the vehicle it began to overheat. We immediately brought the car back to the dealership, the mechanics looked it over for overheating and told us it needed a new radiator. They had the Radiator, Fan blade, and fan clutch replaced and charged us $340.27. We came and picked up the car the moment we drove out of the dealership thick white smoke started to come out of the exhaust. At this point we where very discourage with the vehicle. We brought it back and Ryan Wigmore (Owner) said they would check it out and get back to us. We received a phone call telling us that we needed a new head gasket. David spoke with us directly and told us he felt really bad because we had just purchased the vehicle less then a month ago and there where all these problems. We where shown a print out of head gasket work and where told that we where being cut a deal for a new head gasket. We where told that the labor costs would be very low and the majority of the price would be for parts. We where charged $374.50 for the work. A week later we picked up the car and set up a payment agreement. We paid off our balance and then 2 weeks later the car start overheating again. We brought it back to the dealership once again. We began to wonder why a car with such low miles would be having all these problems. They looked over it and called us and told us now we need a new engine. We asked about the head gasket and Ryan told us that they just steel sealed it and tried to see if that would work to save us money. Steel seal cost $90 and about an hour max for labor, we where charged $374.50. We never received any signed paperwork from Ryan stating that they where doing steel seal which we where told was a head gasket. We where told that they would replace the head gasket for a discounted price. Instead of fixing the head gasket like we where told by David, they poured steel seal into the car, without our permission. We thought we had a fixed/new head gasket and where unaware we where driving around with steel seal. So now the engine is destroyed and we need a new engine. We asked multiple times for the written paperwork stating we gave them permission to use the "Steel Seal" they said they do not any signed paperwork for those repairs. We have owned the car for 3 months now and had to bring it to the dealership 3 separate times. We found out that the car actually had 193,215 original miles on it at the point of sale.The misrepresenting of the 1993 Ford Explorer by David Franciosi induced us into a contract of purchase for the vehicle, which we would of never engaged in if we knew that it had 193,215 miles on it.