Is Vodacom taking chances here?

I CAREFULLY meter my phone when it comes to data usage. I am aware that for the February bill the account was seriously high. I metered almost 10 GB data on my phone. Understandably the bill would be high. In March, I meter only about 5.2 GB. Yet all my data charges are just 75% of February bill. Due to being ill and not needing to use the data so much, I have not purchased as many data bundles as in February. <br> <br> I want an explanation and detailed analysis of this is the case.<br> I also requested my invoices be sent via email but I see nothing. Why?<br> Why is it that when I use half the data I dont get charged half the price? This looks like ****************. Please convince me otherwise. <br> I do not think you are really billing my account but probably are including delayed sms notification billing as well as estimating. I currently have a R1500 bill though I only bought 1 x 1GB bundle. What is happening here?<br>