Vodacom SIM Insurance Contract Fee - authorised ?

SIM Contract insurance fee

For the second time, I have been charged what appears to be an unauthorised monthly SIM Contract Insurance fee (despite on-going difficulties, a refund for the first deduction was eventually received). Despite many requests for proof of authorisation, Vodacom have not provided the requested document. While the monthly amount is not significant, a practice such as this could result in significant revenue given Vodacom's customer base. I would suggest that every Vodacom customer check their account in order to ensure that all monthly charges are legitimate. Given the complete and utter ineffectiveness of their Customer Support service, an investigation such as this needs to be referred to an Ombudsman. Is their such a thing ?