Later, Arnold explained to police that he was "uncontrollably angry" about being harassed and that he didn't owe a debt.
Today he pleaded guilty at Christchurch District Court to a charge laid under the Telecommunications Act of offensive use of a telephone.
Defence counsel Tony Garrett said while Arnold was apologetic, it wasn't surprising that, as he told police, he just "blew his top".
Judge Jane Farish said she could understand why he lost his temper.
But she reminded Arnold that if he loses his temper, he must keep expletives to a minimum or else he'll end up in court.
In the circumstances, she agreed that a conviction and discharge was appropriate.
Arnold thanked Garrett as he left the court.