Had a jerk bill collector call us years ago from San Jose, Ca, and was unbelievably threatening. I told him ( wasn’t serious but acting ) that he chose the wrong people to threaten, that my brother and I would track him down, and bury him alive in the Santa Cruz hills. Funny, he never called again.
Many people have gone to jail for similar threats against bill collectors. You’re lucky the collector himself was over the line or a tape might have been delivered to the FBI.