SERIOUS HELP! Oldest child hitting nanny

Hello everyone!

I’ve been a nanny for three young boys ages 1, 4 and 6. The problem I’ve had and always had is the oldest constantly hitting me in different aspects. For example, if we are sitting down talking he will use his feet to kick me (usually hard enough to know that he’s doing it wrong) or lightly put his hands on me or will actually hit while acting like it’s funny. Now of course the 4 year old has caught on but he doesn’t do it often if not hardly and the baby copies everything he sees but that’s a different issue. But tonight in particular, we were all playing a game and when cleaning up I was talking to the 4 year old when the oldest throws a bag of plastic gems at my face for literally no reason. I sent him to his room for a time out because he had many warnings to not hit. Usually I tell the children if they hit, I will no longer play with them (in whatever we are doing.) or I’ll be really serious and explain why we do not hit to hurt people. But tonight has really crossed the line, I mean throwing something at my face? I really need some serious help. I’ve talked with the parents but I still feel like they are trying to figure out the hitting too. Too add, the 4 year old and 6 year old are constantly hitting each Luther. I’ve already gone in depth about the consequences for hitting and how it hurts people, not to use hands, etc.