I have been working as a crew member for McDonald's for around a month now, however I am so over it. They always make me work overtime or call me in to do other shifts on short notice. The pay is also very very low. Tomorrow morning I have a shift from 11am - 5.30pm but I really want to quit before then. How should I quit and when should I tell them that I quit so that I don't have to work for tomorrow either?