Data and Airtime dissappearing although the cellphone is switched off while I am asleep

I woke up this morning at 05:50am and switched my cellphone back on just to find that I received 5 sms from Vodacom at 22:11, 22:16,22:22, 22:20 and at 22:33 to tell me that I am using all my cash and data and have run out of airtime and data and now have nothin left - no airtime and data, yet my cellphone was switched off and I was already asleep. How is this possible. I am training all week in another city and now have no airtime and data to contact my clients. SHAME on you Vodacom, this is the second time in 3 years that you take airtime, money and data from your customers.

PLEASE investigate urgently as I need my airtime and data for my business.