Unauthorised subscription services

The past few weeks I have noticed that my airtime is disappearing. I went to check if my number was subscribe to anything and got a sms that I'm subscribe to a "Befit". I have tried to contact vodacom via their customer care line, 135, their talkbot, but without any luck. I have stop the services, however I want my airtime back as I did not click on any subscription services. I cannot get hold of them as they are always experiencing high volumes.