I had that happen to me where a hospital turned a bill over to a collection agency and it kept bouncing everywhere but to my insurance! Luckily I worked for a large nonprofit association and it had a legal department and the head was an old boss of mine and told me what to say in a letter to the legal department of the hospital!

I suggest you do that, write a letter to "Legal Department" Umtiumph Hospital and give them all the facts in your case and they'll take care of it. They don't want a law suit when they're clearly to blame.