I'm not the one who banned you, but let me just explain something to you here.
I can see how, assuming you're telling the truth and you really didn't realize there was a problem with what you were doing, a ban might seem a bit harsh. However, not knowing the server rules doesn't excuse you from breaking them, just like with laws in the real world. Whether to kick or ban is for the admin to decide, but if you were running around for a long time, immortal and killing enemies, ignoring all requests to fix the bug instead of exploiting it, I can see why whoever it was might just opt to give you a time out. It probably won't be for very long, so my advice is that you just wait it out.