Vodacom hunky dory ****

I have a contract with Vodacom in which I receive R200 of airtime per month. A few days into September I noticed that my airtime was disappearing fast, even though I had only made two short calls and bought R29 of data. This continued: every time I looked at my Vodacom app, my airtime would be less. I thought that Vodacom was suddenly charging me OOB rates even though I opted out. Using the USSD system on 13 Sept, I discovered that a "hunky dory" subscription had been added to my account on 1 Sept. It subtracted R10 per day for 13 days, *****ing R130 of my R200 of airtime. I received no notification of the subscription, have never heard of it and have never subscribed to anything. I see that there are many Vodacom customers who have had the same shocking experience with the very same "subscription" ****. Interestingly, FNB notified me on 2 Sept that Vodacom had added a new debit order on 1 Sept, but as the amount was the same, I thought it was okay. This makes me think that Vodacom was responsible for adding the subscription, which started subtracting money from my account that same day. I expect a full refund from Vodacom.