No help to clearify outragous data billing

Vodacom has been my internet supplier for just over 2 years now. The package I had was for 3G + 3 G midnight owl for R168.99 on an open line - I changed it now to a caped line for the same price, but half the data. I have always monitored my data usage and was shocked when my December bill was R696.31, January R472.26 & February R415.72. After numerous phone calls to *** and trips to their Walk-In-Customer Care Centre in Canal Walk during this last month or so, I've only received 1 itemised billing, which doesn't tell me much, but I have already been charged for 2 (Des & Jan, but would now also like one for Feb). Nobody can help me with the required information to establish what happened with this 3 months billing, for a time in which I was unemployed. I would like a complete breakdown of my uploads, downloads, session details ect. The latest ref no I was given on my last visit to the Walk-In-Customer Care Centre in Canal Walk was 53-8XR3W-WV3GZ.