need some advice from other mamas EDIT !

Sorry if this is a little long but here it goes. My 9 year old daughter comes home every day upset and crying because of a kid in her class (also is the neighbor kid) because he is bulling her so bad this has been going on since summer but has gotten worse since school started happens on the bus as well. He will take things of hers ( like gum erasers etc.) and then has the nerve to tell her to fuck off ( he is 9 as well) and to mind her own business whennit actually is her business he eases his fists to her and  calls her a stupid retard witch my daughter is not by any means. I have spoke with his mother she does nothing about it I have spoke with the teacher and principal they said they will "look into it" and I have spoke with the bus driver he said he will do something about it. What gets me is that there school does not condone bullying by any means but yet tells me there may be nothing they can do about it witch pisses me off. One thing you don't wanna do is fuck with one of my kids or a pregnant hormonal mama for that matter lol. A little back story my daughter is 💯 % against bulling and she is afraid if she tells him off she will get into trouble. The little boy comes from a broken home where he and his brother have seen countless times there father beat the shit out of there mother. There father has told them that they never have to listen to a woman because they don't know there place in this world and that it is ok to treat women like shit. Over the summer my daughter came in from outside crying and when my husband and I asked her what was wrong he said her arms hurt they were all red and had welts in them then she said that the neighbor boys used her arms for tug of war and that there mom watched and didn't say anything to stop them   So my husband went right over and told them that if they ever touched any of his daughters again they would be in big trouble and told there mom to step up and act like a parent instead of there friend. Now they don't do anything like this when my husband is around so it's always when I'm home but as soon as hubby gets home they run in the house and stays there. I'm at my whits end with these little fuckers. Sorry not sorry that's what they are any advice on what to do would be great EDIT. I forgot to add that the second day of school he took her water bottle out of her backpack and smashed it on the floor then laughed about it. And this is the same kid last year who took his backpack with wheels on it and swing it and gave my daughter a black eye I was on high I went to the school and bitched about it and nothing was ever done he never got suspended nothing