MTN's consistently shocking lack of support

In the week since my phone was ******, MTN has failed to do a SIM swop. Phoning 135 is useless because the consultants are powerless to do anything. Phoning technical support gets an engaged tone (oh the irony). In store consultants make promises they don't keep. And when I try to cancel my contact, I got a message that the retentions centre was closed despite it being 16:00 on a Friday where they claim the opening hours are until 17:00 on weekdays. I cannot fathom how a company that operates like this can be successful. It's just pathetic how little they do while claiming to 'brighten your day's.