Plan doesn’t cover any of the things we were told it did. Is there no way to change plans?

My family is so tired of dealing with insurance. We didn’t like our plan last year but needed help navigating which plan to switch to for the current year, so we spoke with an insurance broker for help. We named specific doctors and medications that we needed to have covered on this plan, and the broker helped us find a UHC plan that would cover those things.

Except it didn’t and now it’s too late to change plans apparently. We’re very confused because it feels like we’ve been duped almost. My parents can’t get their medications covered, which they’ve been on for years, and had to be switched to different ones. My mom also wanted to continue seeing the doctor she has a long history with for her health problems, but apparently the insurance company doesn’t actually cover that doctor anymore. My mom is just about to pay out of pocket to continue seeing this doctor for care. I can’t even see my own PCP anymore either and I’m also considering just paying out of pocket to see my own doctor, too. We have a marketplace exchange HMO plan so out of network care isn’t covered at all.

I’m assuming what happened was, in the time between when we first enrolled and when open enrollment closed, UHC or the doctor’s offices or whoever updated their contracts, affecting who and what is covered for the current year. So our plan may have covered everything last year, but in the new year, something changed and now our plan doesn’t cover what it used to. My parents are pissed, reasonably so, because if we’re going to pay out of pocket for our care, then why are we paying hundreds of dollars per month for insurance that’s not helping us regardless?

How is anyone supposed to enroll on time and be secure in the plan that they have if they don’t know if that plan will actually continue to cover what they need past the enrollment dates? For once I thought we were on top of this insurance mess but it feels like we got screwed over by the system again. Does anyone know if there’s anything that can be done? Can I submit a complaint to the DOI of my state? Or are we just stuck like this for the next year?