My favorite was a reason I stopped going to a major famous hospital's outpatient clinic in my area, which was that their billing department would sell things to

My favorite was a reason I stopped going to a major famous hospital's outpatient clinic in my area, which was that their billing department would sell things to a debt collector that were paid, and when I called, they'd say you shouldn't be getting a notice our system says paid in full, and I'd say "well, then why do I have 12 debt collector notices with those IDs". I suspect they were just opportunistically selling it faster than insurance paid them, but the harassment of cleaning that up every so often was exhausting (since the hospital would always say "well it's not on our end"), combined with a bunch of other shady things the place did. The dumbest part was, they were like, $10 bills, so I can only imagine how cheaply they had to have been sold for the debt collector to think they could turn a not-loss on it...