Being billed for a subscription I never subscribed to

My husband bought me Vodacom airtime for R100 last week and it just vanished in no time and a friend of mine bought me Vodacom R55 on the 13th of January. That also vanished. I decided to call Vodacom and they informed me that its a Vodafone subscription which I never subscribed to. This is very unsettling Because I cannot afford to be loosing airtime and on top of it to something that I didn't give consent to. I managed to cancel the subscription but today 15th January 2018 I receive another message stating that the subscription will be reactivated. Now this is getting out of hand and I want my airtime back. Hope this will be taken as a matter of urgency.