Even as a paying customer of Google Apps (albeit only for one user), I've got no way out without losing access to all my paid apps - and that's Support's official answer. I suspect in Australia I could take Google to small claims court and get some money back but I'm not sure I have the time or energy.
That's my situation as well. The customer service agents pull the "it's not my department" card whenever I try to cancel my apps account and move my Play library over to a standard Google account.
