BILLED R20/DAY FOR OPERA TELECOM

I have a data contract with Vodacom. For the last few months I was billed over R500 extra on the account. I cancelled the contract last month, and when I asked about the extra charges, I was told it was a subscription and they will cancel it. I received another bill this month that still includes Content Services. I have never subscribed to this. Being a data contract, the sim card was always only in the router, therefore I could not have accidently signed up for anything.<br> How can Vodacom allow external companies to charge my account?