Navigating antepartum billing

I find myself in a weird situation and could use some tips on navigating it. Anonymous because of the specific details.

When I first became pregnant, I had an EPO plan in Southern California. My employment ended (planned transition) around halfway through the pregnancy in May, and I moved to Florida. It was 6 weeks between jobs. During that 6 weeks, I signed up for Florida BlueCross (BlueOptions Bronze 24J01-06) through the marketplace for the month of June, since COBRA would not cover me in Florida anyway. Once my employment started on July 1, I was then covered through Aetna.

In May, I began seeing a new obstetrician in Florida. They decided that instead of billing E/M for each visit to blue cross and then to Aetna, they would charge me self-pay for the global prenatal and delivery care, and then submit the global care charge (59400) to Aetna when I became covered and reimburse me what insurance paid them. So I paid 5500 out of pocket when I DID have BCBS coverage because it was a more “straightforward” means of billing according to the practice. I have the baby, etc, and am now trying to sort out the billing situation. I saw my current OB 4 times before I delivered, and a different OB actually performed the delivery because she was out of town when I went into labor. The first visit at the end of May I was uninsured, the next 2 I had BCBS, and the last and during delivery I was under my employer sponsored Aetna plan.

At this point, I have already met my deductible with Aetna and out of pocket costs because the labor and delivery, hospital charges, etc, have all been processed. The practice is telling me they submitted the claims to Aetna under 59400 and Aetna is covering $1800, and I am responsible for the rest.

My question is, what do I need to ask the practice to do to straighten this out? Do I ask them to change the charges to individual E/M codes for each visit and bill BCBS and Aetna separately based on dates? Do I ask for receipts for the payments I already made and submit to BCBS for reimbursement for the month that I was covered by them? The practice seems to not have a great handle on what they are doing, and I don’t think their method of using the global billing code is appropriate in this situation, but I already paid their out of pocket fee and am now trying to get reimbursed for the periods I was covered during my prenatal care.