Opera Telecom - excessive service content bill

I realised today that my Internet account with vodacom was R800 for the month. This in comparison to a normal R150. Upon investigation I found that there had been charges of R650 for service content. This was quite a shock. I also found a R50 charge for January. I went to vodacom in the Mall@Reds and was greeted friendly by the consultant in the shop. I explained that my account was excessive with service content and he subsequently, in a rude manner, said they cannot be responsible. I asked him what can I do and he said go to centurion mall. Again I asked him if we can please phone them and again he said very rudely that he cannot. Upon my question of whether he can please give me their number he simply said he doesn't have it. Pretty poor in my opinion. I do not know how the service content got onto my account but i feel it is unacceptable that vodacom can simply say it is not their problem. The name of the service is Opera Telecom. Please give me my money back as I certainly did not ask for this service.