Permabans are just plain dumb. I get the reasoning behind it, but that also doesn't make it right. The only time anyone should ever be permabanned is if they are cheating. You literally already have a system in place to deal with these people. Chat restrictions are effective and I could even support permanent chat restriction or revocation, only allowing pings to communicate with the team. I truly believe you have gone to far and let your power get to your head and have become the bully you seek to repress.