TELKOM Is charging for a service ever month - which was terminated 8 month's ago!

After being a customer for over 30 years (with the same telephone number) We have terminated our telephone service with Telkom in writing at the end of November 2018 - sold the premises, and moved to Europe. Since then we receive an invoice every month, and the amount has now accumulated to almost R 5000.- Several attempts to reach Telkom via e-mail and telephone have been unsuccessful, they simply do not reply. It is a sham that one has to deal with an organisation that appears to be *********** and one has to spend time and effort to over 8 month's to do something as simple as a cancellation.