Unfair data charges

I have a 2GB allowance on the most expensive Red Advantage package and still have to buy data bundles throughout the month, even though I use WiFi at the office and also at my home. Firstly, I cannot understand how I use more than my allowance during the month, but to avoid out of bundle charges I purchase data as soon as I get an SMS warning me that I only have around 800MB left. During the month of June, I allegedly used R1,131 worth of data, outside of my bundles!!! I fail to see how that is possible and logged a data dispute. Surprise surprise, the outcome of course was that I did indeed use the data and I was bombarded with tech talk about tickets and towers that I 1) do not understand and 2) do not care for. Having been with vodacom for more than 15 years and having 4 lines with an average bill of R1,800 per month, I found the outcome utterly disgusting, unfair and unpalatable. It's time to go to MTN, I think.