Bullying and Stress

sorry for the long post,please dont put this on facebook.
My daughter is in year 1, and is a pretty good kid overall. thi year she has been getting migranes and headaches which are only getting worse. when sh gets them she doesnt want to do anything. normally shes a very active kid. ive been to the dr and paediatrician and medically cant find a cause and have suggested it is stress related and we need to nip it in the bud now. Her dad is in her life when it suits him and now lives in a different state and works overseas. he goes months with out bothering to call to talk to her. she bottles her emotions up because she doesnt "want to stress mummy out/" Now at school a girl that has been saying rude, mean, nasty and one racial comments every day since kindy has gone to far. the other day i picked my daughter up to discover she had a large cut rom her arm pit to her elboow from being pushed into a fence. this cut had two bandaids on it which wa put on by her friend not the duty teacher who was told about this she was told to wash it herself, and didnt even get told to see the school nurse who is there full time! the teacher didnt bother to call me when the incident happened at lunch, she told me about it whn picking my daghter up infront of other parennts ad her classmates. My daughter aditted topushing this girl first which i have expressed to her is never ok. She pushed this gil, after telling her not to follow her and to stop it, my daughter got bcked into a corner by this girl, and has obvusly had enough of 3 years of this crap where the school has done nothing about it, and is fully aware.i have sent photos to the principe of my daughters arm. and she has said she willl get back to me in afew days. This girl bullies other children as well to the point they are scared of her. My daughter and her two friends and the bully got called into the deputys office all together to discuss what happened. this little girl (bully) got a chance to say her side of the story and then the deputy asked if thats correct and the three girls agreed becausethey are scared of this girl. howver this girl has lied and twisted the story to say the other girls were excluding her. so the deputy said for the three girl to be nice to the girl(bully) and not exclude her. The girl (buly) basicaly got away once again with it and for causing harm to my daughter. Myquestion is has anyone had a similar experience and what did you do abut it? I want to pull her out as im paying almost $8000, for this crap to happen when the school has won anti-bullying awards for its anti-bully campaings/programs. They also sent out a letter to say they are increasing the fees once again. and im a single mum, and i purposely stuck her in this school not not go through siilar stuff that i went through. Please no comments about kids being kids nad that theres bullies everywhere i realise that but at year 1 these things shouldnt be happening at all especially not in year 1. TIA for your advice