i was required to pay my portion of a cardio scan a few years ago. when they asked me how much of the bill I wanted to pay I told them “all of it”. I left the hospital given potentially fatal (incorrect) advice about what activities I could safely engage in.
a couple of months later they sent me a bill requesting additional payment for the scan. I called them up and told them I had already paid for “all of it”. the finance lady shuffled some papers for a while then came back on line and told me to disregard the bill.
Three months ago my wife tried to negotiate with a hospital on a bill she’d gotten. The woman told her she couldn’t accept a lessor payment until October. We have know idea why. My wife sent a check with “PAID IN FULL” in the memo section. They cashed it. We keep getting bills for the difference so we sent them a copie of the cancelled check. We believe the bill will stop coming next month.