Need help navigating UMR through Nevada PEBP

In May of 2023 I thought I had a severe toothache and went to the dentist. After an xray he found a mass in my neck. It turns out I have a saliva gland stone. This shit hurts like hell everyday and seems to be in a constant state of infection. I can feel the pain in my ear, throat, teeth and neck. I was referred to an ear nose and throat specialist. He told be that I need a sialendoscopy (endoscopy of my saliva gland). He referred me to UC Davis but they said my insurance was not accepted there. I have contacted UMR 8 times now asking for a list of providers or facilities that perform the procedure I need. They refuse to give me anything helpful and basically just say it’s up to me to find what I need. My ENT doctor told me that no one in Nevada performs this procedure but my insurance should be contracted with a center of excellence that does(never heard this term but UC Davis is considered one of these). How can I get this information out of my insurance mafia? I’m just feeling helpless and angry with the whole situation. I just want a yes or no from them about whether they cover it or not.

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