Vodacom Billing

In December I was billed for data usage on one of my vodacom contracts. On 10th December 2016, I was billed over R4000 for out of bundle usage. I contacted Vodacom when I received the bill in January to query this and they emailed me the itemised billing which said absolutely nothing about where the usage occurred, what was downloaded, why part of the data usage on the same day at the same time was in-bundle and the other part out-of-bundle rates. I phoned Vodacom back to query this and they said that they can unfortunately not provide any more information. Needless to say I have refused to pay this in an attempt to get some response from Vodacom, but the Customer service this past week has been laughable. I have received three final demands via sms and email to which I have responded to each one telephonically and spoken to a consultant requesting assistance with querying the data bill from December. None can help me! I have also requested to make payment arrangements all three times I have called and the consultants and supervisors have assured me everything is in place. Yet the next day, another sms; I phone them back, and nothing is recorded or showing on their system. Pathetic customer service is a serious understatement! If you had to look at my usage history on all four numbers Vodacom would see the R4000 data usage in December must be an error that needs to be reversed.