They are not attorneys. They are debt collectors. They will pretend to be a law firm in order to scare you. They want you to give them information about this person. Basically they want you to do their job for them. Ignore them. Block their calls.
No one is going to serve you. As already explained, they are scam artists. They use incorrect terminology & pretend they are a legal firm. They are not. No one will file a case against you, either. Best is not to even pick up the phone.
Received a voice mail at home number stating the same as above but didn't even say my name just said "you" sounded like an automated voice mail. Will not call back or give them a dime definitely scammers