Consistent over Billing

This is the 3rd month where I have had a crazy Data bill with no notification from Vodacom. I have asked that they send notifications through when my bundles are depleted and even installed the MyVodacom app which sends Push notifications through. I acknowledge that I use a lot of Data and I am willing to pay for it, but not the out of bundle rate when it is clear based on my statement that I manage my data bill carefully AND I have asked vodacome to notify me which they do sometimes and then also dont sometimes. Still up to now, I receive notificaitions of howmuch data is left on both my numbers. This function never worked end of February and now I have to foot the bill. This is unfair and as a loyal Vodacom Customer, I feel Vodacom should meet me halfway. Being one of the most expensive countries in the world for data Vodacom are enriching their Income statement and the end customer has to foot this because Vodacom are not meeting their commitment to notifications. Why is this a recurrance? Call centre agents are unmoved by my frustrations and are unhelpful.