Worst customer service ever!!!!

This has been by far the worst customer service and company I have ever dealt with. I have been sending emails since November 2023 to follow up on a query which still has not been answered. I have used their WhatsApp number to chat to someone and still to date no answer. My account was settled and still I am receiving emails and messages that payment is outstanding. When I phoned them now, I requested to speak to a manager and no manager was available on the floor. According to the call centre agent, my proof of payment was sent through on Friday and still I am receiving the messages and emails that I will be handed over to ITC but still no reply on any of my emails.