Who pays ER bill if insurance carrier denies authorization of a narcotic you have been on for months?

I'm presently on New York Worker's Compensation. For the last 6 months the insurance carrier has authorized payment of my prescription of Percocet. Last week I submitted my new prescription and it was denied. Contacted my lawyer (who I have just fired) and my doctor. The reason given first was lack of variance which under the Medical Treatment Guidelines is clearly not necessary if it is well documented and consistent with medical evidence. I didn't have the funds to pay for the prescription out of pocket and over that weekend I started having withdrawals. I ended up in the emergency room for chest tightness and withdrawal symptoms. Due to the strict Medical Treatment Guidelines under "Narcotics" this type of medication should never be stopped suddenly. The ER bill because of all the blood work and EKG will be in the thousands of dollars, is the insurance carrier liable for the bill? Can a WCB judge order them to pay it or will I need a lawyer for a civil action. I didn't violate the medication agreement and isn't it the insurance carrier the law that they have to contact my pain management doctor before suddenly refusing to pay for my prescription which they were well aware of and did authorized for the prior 6 months? Thanks for any responses and opinions!