Vodacom *****ing my airtime

I have been with vodacom since 2004 and have been a loyal customer to the service provider but lately I'm always looking airtime and when I call the helpdesk i get told that my number is subscribed on something which I have never authorized, they last gave me a number to send an sms to just to cancel any subscribition which I may have whenever I feel like my airtime gets depleted without usage I have been using this number for the past few months but today I had R14 balance after purchasing data and minutes later I was gown to R9 without using the airtime..:: called the helpdesk and they spun me another story...

I'm really losing faith in the service provider which I have been loyal to for so many years