FORCING INSURANCE COVER

I object strongly to receiving an sms stating that Vodacom have automatically taken out an insurance policy on my account, and that if I want to cancel I have to sms them a code. Surely this is *******????? That is the same as me saying. Vodacom hereby agrees to pay me R 1 000 000.00 within 24 hours. If you do not agree please sms this code to my phone within 1 hour. YAYIMRICH. otherwise this contract is binding. Whilst I understand the insurance cover is only R5 a month, it is the principle here. You cannot legally take out any insurance policy without prior permission for anyone and force them to cancel if not interested. Lawyers please help me out here. Is this *******, or harassment?