How to overturn an erroneous banishment ?

[Pepe Le Mokko]

Hi
suppose, for some reason, one is banished erroneously from the forum. ( Errare humanum est...)
How is it possible to contact a mod or Admin to correct this?
It happened to me yesterday and thanks to a forum member I know of, the problem was solved.
But what if... ?

(And BTW my friend tried to PM one of the mods, but his Inbox was full... What's the point of being a Mod if you cannot be contacted?)