When was the last time you received contact? It's very possible he may have had a family emergency or something out of his control delaying him. If he's told you recently he's busy and provides a reasonable excuse I can see how that's reasonable. At the same time, if you're dissatisfied with the service I would contact the seller and request a refund or offer some form of mediation.
If all else fails and you are certain he is scamming you there is a pretty good guide to dealing with it found here: http://airsoftcanada.com/announcement.php?f=33&a=2