Stuck in a loop with health insurance and provider

I have Cigna and MRIs under my plan are covered 100% (no deductible) if pre-authorized as medically necessary. I got that pre-authorization and it said on the authorization where to go for the MRI.

I made an appointment there, which is 100% confirmed to be in network. But when I made the appt they said they wanted me to pay over $900 upfront bc my deductible had not been met. I checked with Cigna and they provided a reference number to give back to the provider stating I was 100% covered, no deductible as per my plan. Provider said they’d mark that in my file, and in a chat with them they said I wouldn’t owe anything up front anymore. All of this is in writing from both parties.

Fast forward and I see I met my deductible and I question how and why. Well, an EOB shows the provider is billing me for the $900+, while my plan paid $100+. I chat with Cigna on their online chat and they said it’s bc the provider billed it as an MRI in doctors office rather than in an outpatient facility which would mean I’m not covered. But strangely they also saw them listed as an outpatient facility which is why they said I should have been covered in the first place. they escalate to a supervisor who reached out to the provider , which apparently ended in a request for a “contract review” and the Cigna rep said bc Cigna agents promised me 100% coverages, she’s submitting it for a coverage review.

As I was doing that, I was also on the phone with the provider who essentially told me (in nicer terms) to f myself.

Should I be worried I’m still going to owe this company $900 despite all the confirmation prior to the services?