Unauthorized debit for content services

To my surprise and disgust I found that Vodacom billed me for daily wallpaper content services. Not one, but two different subscriptions of this wallpaper service. I did not receive any notification of this, in fact, I demand that Vodacom send me the written instruction signed by myself where I specifically asked them to subscribe me to any Wallpaper content services. When I phone customer service they imp**** that I must have accidentally clicked on a subscription - that is BS! Can you prove that I made use of your daily wallpaper service with a detailed report stating when and where I downloaded your wallpapers? No you can't! Because you royally *****ed me over and expect me to pay for it. As you may know I am cancelling my contracts one by one, check my records, I keep to my word because you simply can't keep to yours.