Vodacom and Opera Telecom billing

Vodacom debited my account with an extra R784.32 which they claimed was submitted by Opera Telecom, a WASP service provider. It is alleged that I subscribed to Opera Telecom and I should contact them directly. Opera Telecom indicated that they can only be instructed by Vodacom to provide such proof. I contacted Vodacom to request proof and they promised to do that, 7 days later I still do not have proof of subscription, when I was told that service providers are given up to 7 days to respond. Someone between Vodacom and Opera Telecom should pay my money back or provide the proof of subscription.