@Multiyman accusing someone without providing evidence is a bannable offence. Also there is a section for this: http://www.mpgh.net/forum/393-private-reports/
Make a thread there, with all the evidence you have against the person. If the evidence is sufficient a middleman will request a ban. However if you yourself did not use an MPGH Official middleman we hold no responsibility for the trade, and it will have to be resolved with the person. Though we will still ban a proven scammer.
Contact any of the official Middlemen with any other questions.