subsriptions deducted

I noticed that airtime was disappearing from my phone. I contacted the vodacom call centre and they informed me that I was subscribed to services such as wall papers and **** sites etc!!! I never subscribed to any such services. The call centre told me that they cancelled it and that it would take 3 days. Only to find out an week and a half later that R80 airtime is missing again in one day!!! I phoned in again and discovered that I was subscribed to even more services that the week before! Vodacom can tell me when or how I subscribed to any of these services. And weren't very friendly or helpful. I would like a refund and this sorted out immediately since I did not subscribe to any of this nonsense and lost hundreds of rands of airtime!