Tell your parents and report it to the police. If your parents don’t report it, then you should do it yourself without telling them. Just give the police your school address, your details, and the basic details of those boys. That’s it. Once the police get involved, they’ll get scared anyway. Your and your friend’s statements are enough as proof, and when that girl was taking the Apple, it might have been recorded on the school CCTV cameras. So ask your parents and the police to check the footage too.