Provider claims not in network, insurance says otherwise

I am at my wit’s end here!

On april of this year I saw a new psychiatrist and paid out of pocket as they did not take insurance. I filed a claim with my insurance, expecting to have them cover 60% of my out-of-network costs, as per usual. However, my insurance (aetna) claims that they are, in fact, a provider that is in network.

I tell the provider this, and they claim that they cancelled their contract three years ago, and that they “had to hire someone because Aetna wouldn’t update their system”.

I told Aetna this, and filed an appeal to have their status as in-network revised to update that they are no longer in network. This, of course, was denied, and they tell me there is nothing they can do with me: the provider has to call and get it sorted out. The provider has told me they have no more info to offer.

Is it time for a chargeback? Am I wrong that it’s on the provider to get this sorted out? It seems really weird to me that they just “didn’t fix” their provider status and that it’s causing problems for patients, even IF aetna has problems. It’s on the provider to clarify their status, right?