Fuggem, he's committed a crime. Get the investigation started. You have his contact info. Dig into it. Bro had a similiar problem. I pointed him in the right direction and he ended up calling the dude's mom. They were some sort of politician in the area. Dude refunded the money. He could've gone to jail. Might have messed up some election, he he. Local police departments usually have someone who handles this as well, They could knock on his door.
Welcome to IC3
The Internet Crime Complaint Center (IC3) is a partnership between the Federal Bureau of Investigation (FBI), the National White Collar Crime Center (NW3C), and the Bureau of Justice Assistance (BJA).
IC3's mission is to serve as a vehicle to receive, develop, and refer criminal complaints regarding the rapidly expanding arena of cyber crime. The IC3 gives the victims of cyber crime a convenient and easy-to-use reporting mechanism that alerts authorities of suspected criminal or civil violations. For law enforcement and regulatory agencies at the federal, state, local and international level, IC3 provides a central referral mechanism for complaints involving Internet related crimes
You might also check out http://www.trollhunters.com/
These guys have been on the net for years. They usually focus on tech sites but I'm sure you can get some good advice. Read the site, too. Lots of good info. Consider sending a paypal donation to keep the site running, particularly if they get it resolved for you. I've traded with several of the mods over the years and witnessed their efforts. They are good people.