May 7, 2014
Your local police Bunko Squad
( https://answers.yahoo.com/question/index?qid=20101025160038AAWDHEs )
your state attorney general's fraud office, and YMAX Corp., since it is probably an individual overseas with a MagicJack calling the US for free. YMAX Corp. is a captive, wholly owned subsidiary of MagicJack and administers blocks of numbers that are assigned to individual MagicJacks. YMAX Corp. accepts subpoenas for abuse of their lines, divulging who registered the MagicJack device (although that may be of little help in capturing them) and can permanently disable individual MagicJack devices.
See:
http://www.ymaxcorp.com
and more particularly,
http://www.ymaxcorp.com/contact.html
Note that the "contact" website gives a clickable link to a "live chat" where you can make your complaint.
It is very unlikely that you will get your money back if the caller is an individual overseas scammer, though. And he can always get a new MagicJack if his gets shut down. But if people remain passive and lazy and don't report this THEMSELVES to the proper authorities and phone companies, it will NEVER stop. And you will be hit again and again and again.