Can I register a car with a title and a bill of sale in the state of WI but the is compicated?

I have the title abd the bill of sale for the car but the problem is the owner signed in the wron. So when i went to the dmv they said he wasn't the original owner for the car so i had to bring him in. Now he's no where to be found. The title also had the purcheser of the car to be a dealership that the guy said he worked for that is also what the name on the bill of sale says. So i'm not to sure what i can do with the car and it sems the dmv keeps giving me the run around. If i cant register the car what can i do with it?