Some employers will have healthcare concierges that help with resolving such issues. An example is HealthAdvocate[1] (no relation). I believe some of these services will take a cut (e.g. 25%) of the money they save for you.

I cannot speak to how effective these services are. My general experience with "proxy" services have not been great, due to inadequate care or training.

[1] https://www.healthadvocate.com/site/product-index/engagement...