Nostalrius Begins - Quality wow vanilla realm (1.12)

Hey, on my character Drayzu I left the guild "Swedish Jazz Orchestra" yesterday in the evening (if you look at ST) and today while I got invited to the guild "Mega" I accepted the invitation but did not enter the guild, afterwards any attempt of inviting me would result in a message "This Player has already been invited to a guild" to the inviting person. Anyone know the issue and how to solve it?

Inb4. I've deleted my WTF folder, I've relogged, I've tried to go off for a couple of hours, then I just got the invitation and again, and after clicking "Accept" the same thing happened

oh and it happens on other chars as well..

Are all of these invitations to the same guild Mega? If so ask the fine people of the guild if they have 321 members, if so, there's yer problem. They are at cap.