Data Charges, Lack of Response & Accountability

I have three contracts with Vodacom. On one specific line, I have had data charges amounting to R2000 or more a month, although there were data bundles in place. I contacted Vodacom, and asked for the itemised billing, where I saw that I was in some instances being charged R500 for 2 minutes and 9 seconds. I had asked them to investigate, upon which I was told to go to the Apple store to check the phone. The phone was checked, and all the data settings were correct. I then went into a Vodacom store to try and resolve the issue, only to be told that I should go to the Customer Service centre. I went to the customer service centre, only to be told to call the customer complaints line. This is unacceptable Vodacom. The charges since January have been in excess of R25000, and you have not assisted once!