I'd really like to give you some good advice, but I haven't found a way of dealing with rude people effectively, so all I can do is sympathize with you.
However...maybe something can be done about these soon-to-be-deactivated members? (Why did they deactive in the first place, anyway?) I'm really tired right now so I can't really come up with any fresh ideas off the top of my head on how to frost their arses, but if I think of anything, I'll let you know. In the meantime, just be super sugary annoyingly polite to them--that way, no one can fault you for being rude back, and they'll just be the ones to look stupid. Which won't look good for their new sorority, either.