Overcharging for data - no data statement

My wife has a Vodacom data contract which gets deducted from my business account. I got charged R417 last month and R495 on 2 Sept for a data contract of R75 monthly. The vodacom application shows that data is carried over so we did not finish the monthly data!<br> My wife spent 2 hour a Vodacom shop to try and get clarity about the extra charges but they could not provide a statement of how much was used per month! <br> <br> How do I get invoiced if they cannot provide evidence about the usage?