Telkom bad service

Sending me threatning messages on my new cell phone number, wonder where they get it :-( Mentioning an account number that doesn't belong to me, never has an account number like that. My landline was cancelled way back in June 2019. The account number that they mention in the sms is also not that account number. Wish they stop with their nonsense and just do what they actually have to do. They should not threaten me with Credit Bureau's. I have an excellent credit record, building it over many years.