Upgraded for months without permission!!! To how many customers is this done to?

Vodacom has upgraded all my contracts without my consent. I have been charged and been paying without knowledge that I was paying for upgrades I never permitted. My statement is incorrect ans needs to be revised and fixed. I have questioned my invoices a couple of times and some of the consultants can’t wven explain what I’m paying for. I’ve been a loyal vodacom customer 13 years and just never expected this. I am very upset and wondering to how many more customers are they doing this to??? How many times do we even check what we pay for especially if you have more than 1 contract, which makes it very easy for them to just manipulate contracts.