I have had a high-deductible insurance plan for decades, which has never had to pay one cent of my medical care, and yet they have routinely denied receiving records of the care that I paid for that should have been applied against my deductible, or they found some "official" reason to block applying those amounts.
I used to call to object and request explanations, and got only endless run-arounds from my insurer. It was exhausting, and I finally realized it was not worth the amount of time I had to spend trying. My daughter, who sold prescription medical supplies, would get the same run-arounds from insurance companies, but it was her job and she got paid to persist. It can take a long time. And it drives up the cost of the medical supplies that companies like hers sell.
She, and friends doing similar work, are convinced this is a tried and true strategy that insurers employ. They just grind us down, and have been doing this, NOT since the Affordable Care Act, but FOR DECADES. More profits to pay the CEOs and stockholders.
I finally gave up asking, and was seriously wondering for the past six years whether I wouldn't have been ahead keeping those expensive premiums and saving them toward the care I had to pay for anyway. But then, what if I'd had some terrible injury or illness? I sure don't want to become a burden to my family or society. So I found a way to keep buying probably-worthless insurance, just in case. It's an evil system, and it's hurting every person who needs medical care, which will eventually include just about every single American.