Bad service experience with unauthorized debits!

The WORST experience for a first time contractor with Vodacom! I was debited for a unauthorized monthly top up DATA for R606, whereby my monthly bill is R399, in total it was R1100! . I claimed it at Vodacom shop and even calling customer care. At the Vodacom shop I was told that it was a "system glitch". I only purchased the 5Gig 30day Data with the airtime I receive with this Contract. What's WORSE is that I never even received a confirmation SMS that I did it!. I WANT MY MONEY BACK! I will not be financially abused for hidden costs! The consultants are even rude and refuse to listen. It's been two weeks already and I had to follow up myself!