Goodluck with your final tomorrow, man.
To answer your question, he's not banned because mods don't want to ban an active member, for what seems to be a troll (understandably). However, I must agree that it was written in the rules of the thread, and you should not be rolling a die & accept someone's terms in the official thread, if you don't want to pay anything.
I can see why nothing was done, but I don't necessarily think doing nothing about it was the best way to go (no infractions, DL Dicing ban, ...)