Phantom Debt

I, and members of my close family, received a text message from a burner phone with the message "MY NAME, this message is from the mediation department. It is imperative that you contact our office at 866-573-7741."  When you call this number, an American man answers.  All he has is your name and telephone number.  He then tries to extort you for a phantom debt, or a debt that is outside of your State's Statute of Limitations.  He threatens you with putting it on your credit report, etc.  When you ask that the proof of debt be sent certified mail via USPS, he then states you should not tell him how to do his job.  When you inform him that you know it is a scam, he becomes verbally abusive and hangs up on you.