Hi Action.
When we play escape maps where the majority have voted against fast zombies, I will fore-warn players at the start of the map to change their classes.
Following, a round or two later, I will be in spec watching for fast. If I see a fast, I will freeze him/her and request (through verbal and text) that they type !zmenu and change to a non-fast zombie class. If they heed my request, all is well. If they do not, I ban them from the server for the duration of the map (usually no more than 30 minutes).
I warn players every round by admin say that fast are not allowed, to type !zmenu, and that fast will be banned.
That being said, I don't recall banning you, and if I had done so it wouldn't have been for more than 30 minutes.
And welcome to the forums.