My mom won't let me have a cell phone! HELP!?

Parents can sometimes be stubborn about things even when they are wrong. Here I do think you are right. Unfortunately it will take a while to persuade your mother when she is so adamant about you not having a cell phone. Just be persistent in asking for one and possibly say it could be a birthday/christmas present. If you have money yourself perhaps you should buy one or offer to then your mother wouldn't have any excuse. Good luck!