Yea call the cell phone ask for his name, don't sound mad or anything, ask him a lot of information but make it sound like a normal conversation. Then find him, and beat him up. If he is too big just shot him up with a paintball gun, please note I send paintball not a BB gun, BB can piece the skin and in a freak accident do a lot of damage Paintball will leave good bruse and somthing to laugh over, but then again I would never shut some with a paintball gun just cause I was mad,
/me ignores his past.