My neohew has anger problems, he is very set in what he thinks is right. Unfortunately for me this means that if I'm ever "cheeky" or "rude" or "grumpy" then he will hit me. He is seven years old but he hits hard. My neice copies him and my sister does nothing to stop them and doesn't encourage them to be nice to me. I'm obviously not allowed to hit them back, I used to when I was 10 which is probably why she doesnt care that they hit me. My neice still tells me what to do and shouts at me and doesn't stop until I do what she wants me to. I'm allowd help with this sort of thing right?
If the mother won't take matters into her own hands, take control yourself. No - you can't hit back, but you can certainly make it clear that you won't tolerate hitting.
Use what tools are available to you. Turn off their video games, take away a toy, etc. If their mother wants to fight you on this, you need to be ready to stand up to her and tell her that if she won't discipline her kids, then you will and she may not like your methods. Don't be bullied by your sister and her kids ... obviously, this mother has no reign over her offspring.
Wooow sounds like they have absolutely NO discipline at all. This is gonna bite their Mother's ass in the long run. Just wait. Not sure what you can do about it since they aren't your own kids... Confront the mom one on one and tell her that it's unacceptable that they behave this way...?
stay away from, not exactly nice, but its better them being abused by kids