Vodacom charges me for Content Services I don't know of

I have a home Internet contract with Vodacom. My sim card is in my router. Today is the 4th time I received an invoice with content services included. Content services I never buy. I called once to have the content services blocked and they were blocked, however the next time I found myself having content services on the number again. It is frustrating to always have to check if I have some content services bought which I don't know when and how I bought them and always to have to pay for stuff I don't even know about.