Incompetence C Fibre

I cancelled my contact in October /November 2020 with no amount outstanding. In May 2021 I received an account for an outstanding balance. I sent several emails to the customer services department and cfibre support. There was a response to say that the system is down and they will revert to me. This was about 6 weeks ago. I haven't heard from them and now I see that they have listed me on the credit bureau! I am so frustrated with their incompetence, which is why I cancelled my contract in the first place. I have never hidden away from paying for anything in my life and I have an excellent credit rating. Now everything is ruined because of their incompetence.. I am looking for the CEO's email address. Does anyone have it?