Overcharged without permission!

I have just been charged for the month of January 2016 R150 more than the contract amount that I signed for in December 2015. When I phoned to query why, they call centre said that in 2009 (yes 2009) that i had asked for a 200 sms bundle!! Really??? they also informed me that I had used part of the 1GB databundle that I was charged for without signing for it and that's why they had invoiced me. Again this is nonsense! I was charged on the 1st January and the data was loaded on the 1st January. I did not even know that the data had been loaded since I had not agreed to it. No apologies from Vodacom except when I asked the call centre agent to confirm that the mistake had been made by Vodacom and only then was there an apology forthcoming. How many other people have the charged for services without permission? there was no offer of a refund either!!