KFC CUSTOMER CARE A BIG PROBLEM

My case number is: CAS-510543. I received a WI-CODE and everytime I go to the KFC in Primrose - it gives an error on their side. I phoned Customer Care on the 30th of October to lodge a complain and the lady promised to phone me back. A few days later she phone me back and said the WI-CODE is still working and that I had to go back to the store and try the CODE again and if it does not work - I need to phone them again so that they can explain the problem to the Store Manager what is happening. I went there on the 5th of November to try the WI-CODE but it once again gave me an error. I phoned the same day and the guy promised to phone me back the next day and tell what is happening. However he never even phoned me back and I am still waiting for an answer. I phoned them again on the 11 November 2019 and the lady promised to phone me back and I am still waiting. Why allow WI-CODE if your system does not accept it? This is pathetic customer care as this is going on for over 2 weeks now and nobody seems to be willing to help and sort out the problem.