Can a treating physician refuse to fill out work comp and disability claim paperwork needed for case hearings?

I've been seeing n receiving care n injections for a back injury from a doctor with a pain clinic ( injections series did NOT help/work) and at last injection session my blood pressure went way low to the point of assistants had to lower my head n raise my feet as I lay on their cot n they had to throw ice and cold towels on me, but none of this is noted in my medical file...so now this same Physician is "requiring" me to get more injections n if I don't he is refusing to fill out my work comp and disability hearing paperwork...I don't know if this is legal or ok to do?