In groups, we get the ability to demote and kick people, but we cannot ban someone from ever getting back in. I know we can do this manually by making sure they’re kicked whenever they join again, but that can be a headache, and it seems like a ban feature would make far more sense.
I’ve requested this so many times 
Naturally, I support this.
I’ve requested this too but this came up on the last thread: “What happens when they just come back on a different account to haunt your group?”
A ban feature wouldn’t really be all that helpful. I’d imagine that preventing the first rank from chatting, ROBLOX enabling us to promote people in our group through our places, and promoting users to the next rank after they accomplished a small task (i.e. winning 20 battles in WishNite’s pokemon game, attending 5 trainings in a war clan training, etc) would work as a nice deterrent for spammers/etc.