Unwanted wasp services

I have now on multiple occasions lost significant amounts of airtime to unwanted and unsubcribed for wasp services. I have called vodacom to inquire and complain about this. I was told there is nothing that can be done other than for me to unsubscribe from these services. I asked to have all future wasp services blocked for my number and was told that this is not possible. This is pathetic. We're effectively being ****** of our airtime and Vodacom chooses to not do anything about it