How do I get a clinician to argue for my health insurance to cover residential eating disorder treatment?

I have an eating disorder almost 7 years in the making. I am looking for residential treatment now, but my health insurance does not cover it. How do I get a clinician to argue for this, and is that even the proper way to go about it? Thanks for any help.
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healthquotes.awardspace.info - here is my health insurance plan. As I remember they can provide such a service.
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