********** BILLING ACTIVITY!

I got a bill for R349 which should have been R149 for my telkom mobile contract..I phoned the telkom mobile call centre. Donald advised that apparently an sms was sent to the phone number to say that if I dont want the gift then I must reply saying no. The fact is I have never seen this msg and My 13yr son for whom I took out the contract can not be held responsible for decision like this. I never ask for the extra min therefore I am Not liable if I did not reply. In no way that not responsding IN ANY WAY should binding and default to liability. I should have an option to go Yes or NO. By not replying I either didnt see the message or I'm not interested. We receive spam sms all day, we do not respond to it. This is ********** and unfair business practice and there is absolutely no record that I accepted it. Please let me know has anybody else been caught by this shocking activity. Are we not protected by this kind of bullying? Please can I get some advise or feedback.