Kicked from Custom Chat Channel

Custom public chat channels such /world have no designated moderator. When the current moderator logs off, the moderation of the channel automatically goes to another character.

If you are removed from the channel by the current moderator, you can simply join the channel again. If you are removed again, you can wait until the current moderator leaves the game, then join the channel again. 

Customer Support does not assist with regaining access to public chat channels.