Canceled Line haunting us 3 years later

Our WiFi was canceled due to an amount that is outstanding on a landline that was canceled in 2018. We have previously paid this amount in the hope of this issue being settled but it is still on going. We had went to Telkom Rosebank on numerous occasions to sort this out, and we were promised that this would be resolved. We are currently working from home due to the Covid 19 virus, and it is unacceptable that the WiFi is cut for this reason. Did someone at Telkom not update their books or systems as we getting this notice 3 years later?