Months after my last real procedure in a hospital, even after the insurance was settled, I could not get them to tell me how much money I owed them. Even when I went in person and told them "I want to pay you all of the money right now" they just shrugged their shoulders and told me they didn't know how much I owed them.

They just sent me a bunch of small bills in the mail one at a time and had a text field online where I could blindly pay them without indicating whether or not I had completed my payments.