I'm not so sure. There may be something in the governance of grievance procedure in your state that mandates that the client's preference be honored until the grievance is adjudicated. Since they haven't paid her, I'm assuming despite what they've said, the grievance has not been formally settled.

I can see where this would make sense in a medical situation--say a patient was undergoing a specialist treatment at the time of the grievance being filed. It would work against the patient to have treatment interrupted, and probably require a new medical assessment for malpractice purposes, if for no other reason. So it is to protect the patient's continuing care.

You can check your state's Dept of Insurance, rather than the individual company, to find out how the grievance procedure works. There's also usually a time frame for the adjudication; I would have thought @ 6 months in most states.