Vodacom Data Charges

I received a Statement in 2018 which showed that I suddenly owe them R4000-00. When I queried this no one could help me and advise that I have to pay same. (went to Vodacom branch in Nicolway) I explained as well in the 4 years contract I had, I never spent this kind of data. I needed to find out why all of a sudden it is so high. No explanation was given. My services were cut and I have paid R3000- and it never showed on my account, although I have sent an e-mail with attachment to them. After phone calls still nothing, then an attorney phoned my on behalf of Vodacom and said I have to pay ......now over R6000- where this came from I do not have a clue. I also sent numerous e-mails to Vodacom customer services to cancel my contract, and up and till today no confirmation!!!!! I decided that I will pay only R200-00 as it was an inconvenience for me and that I never got any feedback from them with this regard. I also sent the payment to the attorneys and they have not let me know the outcome from their side as well. It is useless to query, as Vodacom just cut you off and you sit without any communication. Up and till today still no feedback. I heard from my friend that she also got billed now for data of R4000-.... she has been with them from the time cellphones started. (this is just for info... she is taking it up with them as well) the point I would like to make is that this is rediculous and no services. but we have to pay .... pay....pay Most of the times I am on our Wi-Fi at home and at the office, and do not understand this type of billing!!!!!!!!!!!!!!!!!! What do I need to do to get this cleared, from a unhappy customer.