Waited an Hour for nothing

Been at the centre for over an hour waiting to see a dentist. Several people whom have arrived after me got seen to before I was, even theemeemergency patients as which I was classified as. No one even bothered to try and assist me in the matter and carried on with whatever they are doing. Is it not first come first serve at any place regardless if there was an appointment that was made or not? Any doctor's room and hospital operates that way so what is the difference?