george green school / racial attack

my son was attacked whilst in school the incident was caught on camera 10 asian youths kicked and punched him nearly kicking him of a balcony the school later said they would enforce what they call an abc on the ring leader i have recently learned the abc was not done and the child is still causing problems for other pupils in the school the whole of my sons year were outraged as it was found to be a racialaly motivated incident the school police officer has only just heard about this what is our course of action now as the school does not appear to be taking the nessesary steps to stop this outrageouse behavier .?