airtime depleted in seconds?! even though mobile data turned off????

<p>Great so I get the sms that my airtime and data is depleted, I switch off my mobile data till I can buy a data bundle so I recharge R100 airtime, check my balance on the vodacom app and *111#.. I think allright maybe it is just slow.... check again and there is nothing, even though I received an sms from vodacom thanking me for recharging there was still nothing showing on my balance. I think maybe it is technical issues, and a request a detailed summary of my balance from the *111# option...I get the sms at 20h53... still nothing shown on my balance. I call customer service the next morning whom explain that my phone used the R100 in seconds which is apparently possible even if your phone's mobile data is switched off and even though I know for a fact my phone is unable to make any updates without permission to use mobile data. Anyway Vodacom says they will call me back and they don't. The second time I call again, same story but additional suggestion of going to a store but that they will also call back and let me know this time what was taking my airtime, still no call.</p>