Telkom has me strangled

In December of last year I canceled my account with Telkom. After this I kept receiving invoices, I queried with a number of staff members and sent over 20 emails.

It turned Telkom associated my account with the incorrect person, because they sent me a copy of someone else's ID and their cancellation request for a service I do not own. I confirmed this is not me and realising their mistake they quickly admitted they were wrong and it would be canceled with all remaining charges nullified.

Since then I have received further invoices even after receiving 2 cancellation confirmations and now I have been handed over to their lawyers. This has now negatively affected my credit record. How am I supposed to get out of this?

I have proof of all of this!