Telkom account cancelled my account .... but still handed over for Debt Collection

Our account was cancelled sometimes last year, the cancellation was confirmed, (Ref#, ********** 3, "Cancel Service for ...")

I have not heard anymore from Telkom until today from some unknown company "debt-in.co.za".

I log online to check "https://selfservice.telkom.co.za/digital/dashboard/", but 3 other numbers appear, not my old one.

And it says that we owe nothing at all on that account, there are no bill to view, nothing.

How can we confirm that:

- The account was indeed cancelled. - Nothing more is owed. - Who are those "debt-in.co.za" people and how did they get our, (somewhat wrong), details?

Thanks

F.