From the data that you have on him get the contacts of other members of his family and talk to them about it. Don't say he robbed you just mention he's taking too long to post the item and you plan on getting justice to take action if he is dishonest.
Hold on on physical retaliation or at least don't post in forums that you plan to do it, otherwise you might just get caught and then you're the one having problems with justice, even if you just plan on robbing him as he did to you.
Having someone or a bunch of friends pick it up for or with you is a good idea.
You should also consider that the guy could be watching these same forums:)
A few years ago a group of guys here on this site, including me, lost more than 300€ on an A1200 PPC card that was sold by some german guy to apparently a whole bunch of persons, probably around 10! We discussed the thing in the forum and someone ended up contacting the local police. IIRC the response came up almost a year later (maybe more, can't remember) and the authorities simply stated that he already had other problems with justice and they couldn't do anything about it. Completely frustrating.
