To me, it's straightforward. They give you a rule book. They expect (demand) that you to play by the rules. Likewise I expect them too also.
When they disregard the rulebook because it doesn't suit them on the day all bets are off. Now you are in no mans land. Stand up to them as you should and must legally and you will find yourself out of a job ( thanks cumlux). You get no thanks from anyone. The industry is in a shocking state and personally I cannot wait to get out!