With SMS proof of cancellation request Telkom still wants money

Marcia, a pensioner of 76 years of age has been having a Telkom wifi for a number of years. Starting from November 2020 she has been having intermittent service and has on multiple occasions reported the fault and even had some technicians coming through to resolve the issue. During December and January 2021 she again had no service and reported it multiple times . On 15 February she again spoke to the consultant when dialing 10210 and eventually phoned the same number on the 16th of February to cancel the service and requesting a reversal of the charges for December and January when she had no service. She received a SMS reading - Telkom Cancellation Case:***9 has been logged for ***. Since then Telkom continued sending her statements and she continued replying that the service has been cancelled, unfortunately not realizing she should not use that email to reply. She has subsequently spoken to Telkom during April when a technician wanted to come and fix her line and again on 4 May each time saying the line has been cancelled. Now the latest sms states that she has been handed over to collections for R3700. Contacting them today, the consultant says that the cancellation reference is invalid and her system shows nothing of the service being canceled. She was also unable to get hold of any supervisor as apparently they are all in meetings. I offered to send her the screen grab with the Telkom cancellation receipt but she was not interested. Thinking that Marcia might have called the incorrect number, I googled and lo and behold she used the number for the Telkom call centre launched in 2020 to "help you cancel services". Obviously there is an issue with the service, but why should this become the customers problem, to the extend that the consultant isn't even interested in the sms proof of cancellation or trying to trace the cancellation reference. This is terrible service.