Useless service/cancellation/billing

So for the past 4 years, I have been trying to close a Telkom account that was **********, I was handed over to debt Collectors due to outstanding accounts The only way for me to close my account and cancel is to pay the arrears. (Proof of payment sent with ID Documentation)

So to keep my credit score, I paid the account in full and canceled my account via Email and via the app on the internet. (Both acknowledged)

Now I have been working and living in Zambia for the past 14 years I do not have an address to even have a Telkom Account.

Now, after 2 years after paying my account and again I get a call from Debt Collectors (New Collectors) to pay my account.

This again is the same account same reference but with more interest rates.

How does one open an account on a name without signatures or authorization?

Where can I follow up on which address this account is?

How, can I solve this issue?