Vodacom out of bundle daylight theft unexeptable

I'm awoken saterday morning with a debit order R5000 over normal monthly bill. I immediately contacted the business department where I was told I was 5gig out of my bundle that's why I'm charged R5000 more. I told them that I refused to pay that amount as it not normal for a person to except that exorbitant type of charge. They simply said I had to. Vodacom have been ripping people off like this for so many years and it's time we as the consumers stand up. This isn't the first time I've had this type of issue it's about the 4th time. They simply ***** your money without any regard and when you phone there call centre's you have to deal with arrogant *********** people.