Report this to the FTC (federal trade commission). I wouldn't trust a link from here...so I assume you smart folks wouldn't either. So search for "FTC fake debt collectors." Good information there for how to handle and what to do to report it.
My wife received a phone call today and it scared her really badly. They said they would repo her car and issue an arrest warrant (they can't do that). We're filing a complaint with them. Fairly easy. Enough of these and there might be some action taken. These guys make me sick. Please do your part, too.
This woman is a fraud. Threatening a person with jail time, may be against the law. They are committing fraud and possibly phone theracy. Please email your local police, file a claim. Don't let these [***] get away with it. I'm doing everything in my power to get her shut down or sent to jail.