Telkom Harrassing 99 Year Old Senior Citizen!

I am writing this on behalf of my 99 year old Father who currently lives in a Frail care facility and is unable to do so: On 26 March 2020, as he was being moved to this facility I cancelled his Telkom landline via the online portal. I went through all of the required steps, including uploading his ID document. Upon completion I did not receive any notification, HOWEVER, I saved a screenshot which proves that the process was completed. Due to a fault on Telkom's side the line was never cancelled and we are now being harassed by several debt collection agencies, this DESPITE my having phoned and e-mailed all of the available Telkom customer care and accounts options, providing the screenshot as well as the evidence that there was NO useage on the line after cancellation. Telkom, you are harassing an extremely frail senior citizen, despite us cancelling his service in good faith two years ago!