Over charging on data

Every month I buy 10 GBs of data for my smart phone. Vodacom keeps charging me for out of bundle data which is impossible. The call agents are not helpful as to why I keep getting charged out of bundle rates when I have data available. When I explain to them that I HAVE data that according to my understanding it should cover any thing I do on the internet including downloads they keep telling me about that Data Usage is then I have run out of data then they charge me out of bundle rates!! BUT HOW IS THIS POSSIBLE WHEN I HAVE DATA!!<br> I would appreciated it someone contact me and not only explain to me why I am being charged out of bundle rate when I have data, I would like a breakdown of what that out of bundle data is being used on. <br> In the meantime I have put a stop order on this month's payment until this is sorted out!<br>