My question involves a consumer law issue in the State of: Oklahoma

My daughter and future son-inlaw went car shoping and found a new car at a local dealership. When i saw the contract it was obvious this was not a good deal. They traded in her car as well has is truck. Both cars are listed on the sales contract but the truck was never taken to the dealer, they kept her car and released the truck to them. The car title is in my name, my wifes name and my daughters name. she signed a power of attorney slip but no other forms on the contract. I refuse to sign over the title due to bad deal. The title reads dad and/or wife and daughter. Not and/or daughter. They said if i don't sign car over she's commited fraud because she said her name was on the title. She's right it is on title but also requires my or my wifes signiture just as she explained to them. She is not on the car note. She was added to the title several months after car was purchased. They need our signiture to do payoff and title change. If we don't sign over title which eleminates the vehicle from the contract is it then a null and void contract. Additional info: Vehicle was bought on a Saturday, Dealer close Sunday and they tried to return vehicle on Monday with less than 300 miles on vehicle. Short of them going to jail or facing any criminal charges I will not sign over vehicle. What are options?