Colonoscopy is non-preventative, is there anything I can do? (UHC)

I am 27 and have been experiencing stomach issues for a few years now. My PCP recommended me to a GI who, after discussing my issues, had a Colonoscopy performed. This week I was just billed $3700. My in-network deductible is $5000 and a max out-of-pocket of $6000. My plan is only covering 30% of the total costs.

I guess this is my fault for not ensuring this would be taken care of beforehand but I am pretty concerned. I understand that because of my age a colonoscopy does not fall under preventative care. But I was recommended to see a specialist by my PCP who preformed the procedure out of concern of future health risks. I spoke to the TriHealth billing office and was told that physician care and hospital procedures are different, regardless if I was seeing a specialist or not. My procedure was categorized under “non-preventative hospital care” and therefore wouldn’t be covered. I asked for some sort of documentation describing this but the person on the phone said they could not provide me with anything but instead would mail an itemized receipt in 7-14 business days.

I guess I’m just confused and a little scared. I don’t understand any of this and no one really seems interested in helping. I understand it is probably too late to have something done about this bill but can anyone describe what I did wrong and what I should’ve done differently?