"Kalsariya had no way of knowing then that she was embarking on a crusade that would take over a year, send their bill to debt collections, lead her to complain to the Illinois attorney general, and discover that the hospital charged nearly $7,000 for a procedure that was never performed."
https://www.nbcnews.com/health/health-news/billing-expert-investigated-husbands-er-bill-was-able-knock-thousands-rcna53683