Dr.'s office screwed up my insurance claim, need some direction

Sorry if this is the wrong sub.... Also it seems I suck at reddit formatting. .

tl;dr upfront: .Been getting testosterone shots for a year .Didn't figure out insurance wasn't paying for them until Oct. .Ins. didn't pay because the Dr.'s office never sent them my lab results .As of today, Dr.'s office has received 2 letters from insurance and several calls/emails from me asking them to send the lab results .My Dr.'s office provides my records online, I acquired them today and called my insurance co. and mailed them the records .Also sent a strongly worded letter to the Dr.'s office today .What do I do next? . Long Version:
The outstanding balance isn't a lot (~$700), but I'm pissed because a) these costs should be covered, b) my employer pays a shit-ton for my insurance to cover these things, c) I've done everything I know to address the issue as soon as it arose, and d) the medical provider advertises that dealing with my insurance and handling claims is a service that is included with my medical care. Last April I started taking testosterone shots at my Dr.'s office and was expecting it to be covered by my insurance. Everything went fine, until I got my first bill in October. It was a couple days before I could follow up during business hours. Later that same week my insurance company sent me a copy of the letter they mailed my Dr.'s office saying the claims were denied because they needed my beginning lab results to verify medical necessity. I called the insurance company first and they verified the letter was correct so I called the Dr.'s billing/business office. They said they didn't get the letter, I offered to scan and email it, they agreed that would work and they would resubmit the rejected claims. They also said that I was about two weeks away from some of the charges going to collections so I paid the amount required to keep that from happening but they sent me to collections anyway (I disputed it with their lawyer and he sent it back to the Dr.'s office). I called the Dr.'s office back a few weeks later, it's November now, they told me the denied claims were resubmitted, told me that the next cutoff date for collections was December 29th. I called back in mid-December to pay another chunk and they told me my balance was put on hold until they hear back from the insurance company. I called back in January, Dr.'s office still waiting on insurance company, my account still has a 0 balance. I had stopped the treatment in October when this mess started, by February I was feeling like roadkill again so I called the Dr.'s office, they were still waiting on the insurance company they said. I went ahead and scheduled another appointment to start treatment again, believing the insurance company was dragging their feet on the resubmitted claims. I saw the Dr. and got another shot on Feb 11. He scheduled another lab for me two weeks later. The day I was supposed to go in, I got a bill from the Dr.'s office, insurance denied the claims again and they wanted the balance. So I called the insurance company, and they never received the lab results from the Dr. Then I called the Dr.'s office, talked to the same lady I had been dealing with since October. She said "we didn't know they needed any documents?" I called her out on her bullshit and she said let me read your account notes, which she read them to herself out loud. "...patient called... needed lab results.... patient sent email, letter from insurance company... patient email, recording of phone call attached..." She lol'd for a second about that last one until she realized it probably meant this call was being recorded too. She told me they would resubmit the claims again with the lab results. After that last call I sent their office another email with the first letter from the insurance company attached again, this time I cc'd every one of their directors, the doctor I see is part of a large group, his office is in one town while the business office I've been dealing with is in the next city. Later that afternoon I got a voicemail from the office manager at the clinic I actually go to, she said she's checked on the account and someone from the business office is taking care of it. And so last week I get another letter from the ins. co. This was a copy of a strongly worded letter they sent to the Dr.'s office. They still haven't received the lab results. I called the insurance company and let their rep know I have acquired a copy of all my records from this provider. We also figured out today that my Dr.'s office only resubmitted 5 out of 11 total claims that should have been covered, She told me to mail records along with a copy of the letter they sent back to the claims admin. I did that and then made a copy of everything and included that with a strongly worded letter to my Dr.'s business office. I record my calls (yes, legal in my state). I have notes I took during each call. In the letter I received last week (copy of what they sent to the Dr), there is a paragraph regarding disputes and that under ERISA I have a right to file a civil lawsuit in 12 months. But from what I understand about ERISA, that only applies to the insurance company, not the medical provider? As it stands the insurance company is justified, but the doctor's office has failed to provide the needed documents, even though they were notified by both me and the insurance company, right? So what do I do now if the doctor's office doesn't get this straightened out? I expect I will have to pay the balance soon to keep it out of collections, but then what are my chances of the doctor's office actually following through with the claims after my bill is paid and issuing me a refund?