continued harrassment by children in WA

criminal: I need help two girls how are under age keep harasing my duaghter and I have called the cops twice and they don't do anything becuase they are under age my duaghter is 10 and the girls are 11 and 16 they are sisters I have changed my phones twice so far and I am tierd of changing it what can I do to get a point out to them that they can't bully kid's around.I even went to the school district and when I left the principle told my daughter not to be telling me everything that happens in her life which i was upset but know I know why alot of kids commit suicide around here. - Is this your question? Add additional information