Shady Billing Practices Memorial Herman?

So a few months back, I got a bill from Memorial Herman. It didn’t say what for or have any itemization, just hey, you owe us this amount. So, I called and asked for an itemized bill. They sent the same nondescript bill. They called me and again I requested an itemized bill. They said it was in the mail. I got the same nondescript bill. This went on for a few more calls, always with them saying that the itemized bill was on the way and that I can talk to my insurance to see what the charges are.

Anyways, now a collection agency is calling me. On their letter the collection agency actually had the medical procedure it was for so I was finally able to call that doctor’s office directly. I never received that itemized bill.