The seller has been around the forum for some years and I doubt if he/she would sully their reputation by attempting a fraudulant transaction. You don't say where in the EU you are, but I wasn't aware of any massive hold up in getting packages from the US. It could well be it is stuck at customs somewhere, you should be able to know that from the tracking. You have already mentioned nembo, but it would be a good idea to PM him with all the details.
Not a good idea to charge back until one of the mods or administrators have looked into it.