Cancellation nightmare.

I have cancelled our phone line (with screenshots of ref no) on 2021-12-08. We still get a bill. Logon to Telkom via App or website to cancel again - everything stops working on app and on website. I emailed Telkom (with print screen ref no) and they don't have a record of the cancellation. I am still billed for a cancelled service. How do I reach the right person in Telkom?