First, complaints are seen and acted upon, but usually not commented upon here. The general idea behind this is not to get those trolls even more publicity. That doesn't meen that everybody that is mentioned will be immdediately banned, but some kind of investigation usually happens.
Second, there is a principal problem trying to ban a certain person, when accounts can be made for free. I agree that some solution would be nice, but generally banning an account has only the effect of the person behind it making a new account. That new account now on 0 blacklists, instead of of the XX for the old one.
Your complaint about the problem is valid, but in a mix of free players and paying players there is no simple solition that doesn't suddenly make the free players second class citizens, which, if I understand Stef correctly, is something he wants to avoid.