Help! What do you do as a babysitter/nanny?

What do you do if the child you watch needs discipline, and the parents are home all the time and they don’t discipline? A Child(3 yr old girl) hit me today after saying “I’m going to hit you if you make me take a nap”. I put her in time out. Not 60 seconds later her dad came downstairs b/c he heard her crying and took her out of time out to comfort her…... after I told him what she had done to me! What should I do?