Just frustrated and need to vent

My baby is 4 months old and I have really been trying so hard to be on top of the billing and insurance along with actually keeping her healthy. The pediatrician recommended that we get her a hip ultrasound since she was breech; OK, we schedule that and take her to the hospital where we did all her prenatal ultrasounds. (She was less than 3 weeks old at this point) We had sent my insurance company the document to add her to the insurance, but since it hadn’t been processed and her name wasn’t on the insurance card, the guy at check-in said it had to be self-pay and we had to sign the financial agreement before they would see her, but we should call billing ASAP to tell them that we would be re-billing through insurance. We called the next day, and billing said there was no reason to call until we got the new insurance card. Once we got the new insurance card, we called them and gave them the info, but they had already sent a bill, which they told us to ignore, and they sent it through insurance. Then we paid the new bill after it was processed through insurance. Today, we got a collections notice in the mail for the radiology bill, which apparently was not included in the insurance claim. I am just so tired because we already met our $8,000 OOPM this year, but now we have to pay an extra $532. Can I dispute it? Should I try to call the radiology provider’s billing, or is it too late for that? We thought that both were going to be billed through insurance, and the billing rep said to ignore the self-pay bill, but I guess she just meant ignore the hospital bill, not the radiology bill.

I feel so stupid for doing the ultrasound so early and making this mess, but it’s our first baby and the pediatrician recommended it. Just venting into the void because getting that collection letter made me angry and I don’t want to spend the whole day mad.

Edit: 33(F), Virginia, 65k pre-tax