How do I get him to leave me alone?

There is this guy that I met at school through a friend. He seemed cool until I gave him my number, because then he started hitting on me. I jokingly told him to dye his hair blue, and he ACTUALLY did it. He constantly texts me, telling me he will treat me like the "Queen of all queens", and he kept using lines from a scene I was in for drama about a guy professing his love for me, when he wasn't even in the scene, he was just watching us practice.He persistently asked me to hang out between cles. I told him repeatedly that I was not interested but he just does not seem to understand. Please help me.