Bad service

My son's phone was ****** so I tried to get assistance from vodacom as the phone was bought with the Sim card to blacklist the phone only to be advised that the number used is not a vodacom number and that the number was ported to cell c in 2015. I made the consultant aware that we have purchased airtime, loaded data using vodacom several times and the consultant still advised that its a cell c number. I called cell c to confirm if the number used in the phone is a cell c number and they confirmed that its not a cell c number and even went further to check to which network the is registered under and also confirmed that it is a vodacom number. For a company that's been around for so many years your service is really disappointing.