Abusive player. How to boot?

[Firefly]

I was made Leader of our Alliance. It’s not very big, chat is pretty basic.
A player has become extremely abusive. I booted them from the alliance but they’re still in it. Still abusive in chat. How can I permanently kick and block this person from our alliance?

 

[Bedlam]

Kick him out and close the alliance or put the medal count up.

 

[Shrekx 74]

You can also report them to cs. I had a similar situation and reported them. I don't know if any action was taken, but they never showed up again.

 

[No Angel]

A ban button should be created.