Had a problem about 2 years ago with a purchase, sent the money $290.00 via USMail.... and never got the item... well, I had been smart and paid for the confirmed delivery.  Anyways, the kid who was selling, kept saying that he had sent and had delivery confirmation.  I finally got the bogus tracking number and went to the USPS and they said it was bogus.... well pissed now, I called his home, got his Dad, and had a nice chat, well, still nothing.  I gave up for like two months.  Coincidentally I was in line at the Post OFfice, and happened to talk to the clerk about it, he gave me a form to report "mail fraud"  Well I filled it all out, attached copies of the email he quoted as a USPS number.  About two more months went by, heard nothing.  Then one day in my mail box is a federal subopena to appear in court in Seattle Washington... they were charging the bastard!!!!  Anyways, I met with two feds twice, gave a deposition to the prosecutor and the lil fediddleers attorney, and they pleaded down.  I got my money back, plus some, and he got a record!
So it pays to be persistent.
Goodluck Creamo