Charged for data bundles but charged out of bundle

When I upgraded my phone at the Greenstone Branch in June I asked for a 3G data bundle to be added to my package, since then I have been receiving astronomical phone accounts, I thought that I had been using too much data and left it at that. In July I checked my bill properly and saw that the data bundle had not been added. I went on to the self help website and tried to add it myself, and got an sms to say that it had been activated. In August, I received another high account. I phoned customer service in August only to be told that the service had not been activated but they would do it then. In September, of course, I received another astronomical bill with the bundle still not added. I see now on my October statement that they are now charging me for the data bundle but are still billing me out of bundle rates!! I cannot afford these high accounts and when I phoned customer service last week they told me that they would dispute it with billing and credit me the following month for all these out of bundle charges! Why must I wait till next month? These high accounts are killing my budget and I cannot afford to pay another amount of R2000 to R3000!