If I understand correctly, you have written demanding authorization for treatment for an industrial injury with no response from the insurance company. Has the insurance accepted or denied liability for your injury? The insurance company is entitled to set up a Medical Provider Network and require you to choose a doctor out of the network. Is the doctor you've chosen in the MPN? If you hve all of your ducks lined up correctly, you would file a Declaration of Readiness to Proceed with the Van Nuys office of the WCAB. Are your ducks lined up?
If you don't know quack about ducks, you may want to retain an attorney. There are some great WC attorneys in the valley. Find a good one here at www.avvo.com or at www.caaa.org. CAAA is the association for attorneys here in CA who represent injured workers. Or you can call me for a referral.
In Misouri, a party can be sanctioned by the workers compenstion judge for refusing to negotiate a clearly compensable claim. In your situation, either notice up a corporate designees deposition on the issuse of receiving your demand letters and the factual basis for failing to respond, or email the work comp judge and cc the adjustor and opposing counsel: explain to the judge the failure of the adjustor to negotiate and ask for assistance to move the case along.
This sounds like my average day. If the injury is denied, she is ignoring you. If you did not request Authorization prior to the treatment, she is ignoring you. If you are not in the Employer's Medical Provider Network, she is ignoring you. If the case has not settled yet and you have an OMFS dispute after payment, she is ignoring you. If UR denied the treatment, she is ignoring you. If you requested authorization, UR certified your treatment, the injury is admitted, and you are in the MPN, you probably would have been paid OMFS....
We offer general concepts, but you should give ALL your facts to a licensed Attorney in your state before you RELY upon any legal advice.
Generally, without knowing more about your situation - you can hire an attorney, you can contact the supervisor, and you can file a complaint with the Department of Insurance.
Oftentimes you have to go through court proceedings to get what you are entitled to. A lawyer can advise you whether or not your issue can or should be taken through the judicial process. If no one's responding to you, this may be your only and best option.