[33girl]

You may not be able to attend official events, but if sisters stop calling/returning your calls, stop asking you to hang out with them, or cut you out of their lives...I would venture to say that they aren't really sisters and you need to just terminate and stop wasting your money on a bunch of a-holes.

You screwed up. It happens. Get your grades back up to where they should be and ask for some sisterly support in doing so. And if your sisters don't want to give that to you, again, I'd think twice about whether this is really a group I want to be involved in.