Bad traders

I forgot to properly follow this up when it happened a long time ago, I thought this guy had stopped using the forum so I figured it didn't really matter, anyway...

A while ago this guy said he'd post me a saddle... the saddle never arrived.... he said he posted it but it'd obviously got lost in the post... Refused to give me back any money then didn't reply to me PMs.

I forgot to properly follow this up ages ago when I posted in this thread asking for advice, so my fault on that one, sorry all. Anyway he's started using the forum again so I suggest he be banned. Not sure who to speak to about this.

http://www.lfgss.com/member33235.html

Edit: this happened over a year ago, here's the relevant thread: http://www.lfgss.com/thread94733.html . Again my fault completely for not following this up, assumed he'd pissed off. Anyway he's back using the forum. I'd rather have the 20£ than him being banned, but I don't see that happening.

What's the best way to make sure this gets followed up? Quite keen for him not to be on the forum anymore...