What is SOP???

No but thank you I didnt know who to threaten them with..This is all dumb if you saw the forms...my ear doc has not been paid from JUNE of last year...I am so mad and upset cause its just a huge run around. They paid one doc...same doc HAD to see me two months later on follow up to surgery ...they said no ....but it was the same code and charge...grrrr....would I really contact those agencies and how do I? THANKS