Girl Guides and HST in Ontario

Have the Girl Guides in Ontario neglected to inform girl guide campers about the HST tax if camp fees are not paid by May 1, 2010? Please comment. We've been surprised by a + $90 increase in our bill. Girl Guides stand by the apparent fact that they emailed an updated account bill which warned that the new HST would apply if balances were not paid. We never received that update. Resulting in a + $90 bill added to our account. Has anyone else experienced this?