My biracial 9 year old son!

My 9 year old biracial son has been called the n word 3 times this year in school and was stabbed with a pair of scissors in school. The boy was white and 10 years old and was only suspended for 1 day. How is this called a punishment? My son was then told to use the washroom fir one person. My son had to stay in at recesses and I brought him home for lunch. Why was my son the one to be segregated when he was the one that was stabbed? The school system needs to change and educate these kids to let them know this is not ok.