strange subscription billings on accounts

both my husband and I have noticed extra charges on our bill this last month, Vodacom live,top tone, breaking news, and video box and other strange subscriptions which we never agreed to. on querying with Vodacom they cannot tell you when or prove that you agreed to these charges however they tell you how to cancel it dial *117#. but offer no compensation for the already billed amounts or an explanation on how to prevent other such strange unexplained charges. also if we subscribed to these services how come I never received a top tune saw a breaking new bulletin or a video for my billing? seems like a way to bill unknowing customers until they notice and report it. Easy money