The never-ending battle to cancel a Telkom account

Submitted my Telkom account cancellation on 24th Jan 2018, well within the month notice period they require and with all requested docs and forms. I got no response, despite several follow ups. I have since moved from that address and see I have now been charged my usual bill for the month of March 2018. They ignore emails, and ignore tweets. I was thinking of using them again, now that I am relocating cities, but this level of dishonesty and deceit is quite frightening.