call identity

I phoned vodacom on the 10th of april complaining about a large amout of private calls and which need to be traced. vodacom assured me that they can help me with the relevant information as it will take 2 weeks to track the call. i kept in touch with vodacom and everytime i called their answer was that my request is still logged.So I phone again today where ive been told that vodacom cant help me with detecting where the private calls come from.Im not a happy client now because vodacom is not giving me the service i need