Have insurance but billed for the full amount?

Edited to add gross and state;;; (Florida, 35k a year)

I hope anyone can give some advice because I feel like I’ve been running in circles with no end.

I work for a health care company and went to the emergency room of said health care company back in February. I have an EPO (Exclusive Provider Organization) with my health care company being a high value network provider.

My agreed copay for the emergency room for this instance is $250. My insurance (employer funded by THIS health care company) processed the claim and approved that copay. I finally received the bill for the emergency room visit and it’s the entire $6k bill, as if I have no insurance. They’re saying my insurance didn’t pay the hospital.

I called my insurance company and they said since this is an EPO for a health care company they basically handle the payments with checkless payments, ie it’s all internal within my health care company and the bank they use. The insurance company doesn’t send a check. I’ve called both the hospital billing dept and my insurance and three way called multiple times. The only thing my insurance can do is keep sending my EOB, the billing dept has put my bill on review for investigation so I won’t be sent to collections (for now).

I called into the billing dept today and they said they received the EOB but it’s unreadable because it looks like the printer ran out of ink(wtf?). I had the insurance company send the fax again and will be sending a copay via snail mail.

Since this is a hospital in my employers company I’m thinking to contact HR but I feel so stressed and unsure what to do? What do I say to HR? That they need to investigate this because I have insurance yet I’m being billed as if I don’t? Who can I report to outside of this company about this? Do I get legal advice? I don’t want to lose my job over a 6k bill but it’s like… you people literally pay my insurance why am I running in circles due to this? At what point do I just give up and ask them for an itemized bill and to negotiate and basically pay as if I don’t have insurance? I don’t want this to hit my credit as I’m just barely out of college and want to get a decent start on life.