I know this may be a kinda obvious question, but in your centre console by the window switches is a over ride button to stop the rear windows working. This button isn't pressed down is it, which would stop the rears working? Or maybe the connector has worked loose on the back of this?
Do the rear windows work using the rear electric wondow switches, or the front mounted rear electric wondow switches?
Have you checked the fuse?
Sorry for the stupid questions, but some folk don't check the really, really obvious stuff first. Admittedly, me included, (sometimes).