My mother hit me! Please help?

My mum does this to me except we've never had a good relationship. Its always been like this. Her current boyfriend makes it worse. He hits her and yells at her. She gets mad and does the same to me. I honestly don't know if, unless they leave marks or physically damage you, you can call it child abuse or just discipline. At the moment, I've just resorted to yelling at her not to hit me and running away. Its working but I don't suggest you should do it.