High Bill for DATA

I received a huge bill, and when I queried it, I was informed that it was over R 2 926.32 data for September and now I checked my account there is an additional R 2074.38 now for October, which is not supposed to happen as I have call limits on all my line. We have WiFi unlimited data in our home/office, and it connects immediately, so this is impossible. We went all the way to Vodaworld was I understood they can sort out my query while we wait. There was a very unhelpful clearly irritated lady that help us and logged a call with ref. S3-9L923-3XVJN, up to now I have not received any feedback except for the call to say I owe money on which I made a promise to pay. I have been with Vodacom for 20 years and never had such an account or such bad un unhelpful service.