Agreed, it's a huge mess. Often, you are also not always told when something is even a billable item at all. You can find examples of itemized bills including things like band-aids at crazy inflated prices.
I've received bills from entities halfway across the country with no fucking clue what role they actually played in care. It's completely fucked. No other industry gets away with billing this messed-up and sloppy. And I'm 100% sure some of the errors are "accidentally on purpose".