Reading teacher Mr Coca called my son a dumb ass y...

Reading teacher Mr Coca called my son a dumb ass yesterday and I don't think the school takes this seriously. Met with the principle today who stated she will "speak" to him so I have taken matters further and will be filing a complaint with the District as he should not be teaching my child or anyone else as he obviously doesn't like his job HE chose. And I firmly believe if he has called my child a dumb ass in front of the entire class he has done it before and will continue to mentally and emotionally hurt children he is suppose to be educating and encouraging. Not a happy parent right now and he is so out of line.