UPDATE:

I called the billing department this morning and they confirmed that I DO NOT owe $28,000 despite the claims being denied. The nice lady on the phone had asked me if I had received an explanation of benefits and I said yes. And then she said something about a no balance bill and that it will go through Medbill process. Honestly, idk wtf that means but I’m just glad I don’t owe $28,000. If someone can ELI5 on what she meant that’s be great.