Telkom the Worst EVER!

Received various threatning sms's from Telkom that I owe them money. The account number mentioned doesn't belong to me, never had. Cancelled my landline in June 2019. Then since January 2022 I received these sms's on regular basis. Luckily I still found one of my old accounts, therefore I can proof that the mentioned account doesn't belong to me. What's the matter with Telkom. Are all their employees ***********?