In Cali, if you are on disability, workers comp they cannot legally even fire you until you return. But I have been fired before by then sending me my last check in the mail before. Bullsmurf. But apparently they can do it that way.
I'd go to human resources if they can't help mention that since you feel like your being wrongfully terminated while on workmans comp you will be getting in touch with a lawyer.... slot of times at that point they will give you answer