How do I find Jeff and Roxanne McGraner phone number?

I bought their car through a third party, but can't seem to get to get our title. Jeff McGraner has cashed our check, now we need the title to the car so we can drive it. It has been a five days since he cashed our check. Fortunately, we do have the car. We just need the title to our car. We are having trouble contacting them. Please help.