Remove Anon member from guild when they are not logged in

Essentially I'm trying to remove a player from my guild while they have the /anon function active.

the standard /gc remove doesn't work because it keeps returning back the prompt "player is not apart of your guild"

However the player still shows up in the roster list with the /social command
as well, the player is listed on the herald as apart of the guild

is there a fix or way around this?

Cheers