Same thing. Left a message saying they are a server for the State and threatens to serve papers at work or residence. It is an implication that they are a state employee.This is, of course, illegal and they don't want the identity revealed or they can be sued. If you talk to them ask them for their address. Make it clear you are prepared to go to court, but you need the address so you can send them appropriate documents. They will not give that to you, but once you get that send them a  debt validation letter and a cease and desist letter demanding they contact you through mail.