Theft! Took data away, then charged me for more, all of which I did not use!

I have a 2GB data package per month. I never use this amount unless away for a month. I'm on maternity leave at home all day with our wifi on. On September 4th (4 days into a month), I was suddenly notified I'd gone through all my data and had incurred R200 out of bundle charges. I received no sms indicating 50%, 70% etc of my usage a Vodacom are required to send. The only notification s received were a set of 11 sms's received all at the same moment saying I'd run out of data, then I'd used R1, R10, R100, R200 of out of bundle data, respectively. This was clearly incorrect. I called customer care and have as no if ed they could only log a query which would take two weeks. I requested the itemized billing and was told it would come in a month. I asked what else I should do to be connected to data and was told I simply have to buy more. The query was logged. I received no response, phonecall or resolution but received an sms a few days later simply saying query was closed. As a business serving customers you simply cannot make a mistake with data like that, then deduct R200, then tell me to buy more and close the query with no response, it's complete bullying, and actually this amounts to theft.