My "ex" is calling me and i don't want him to so what can i do?

there was this guy who was a little more than a friend but not my boyfriend. he liked me but i didn't. so i let him be with me for almost a year till something happened and i told him i didn't want to talk to him or see him. he kind of isn't getting it through his head that i don't want him. so he found my new email and emails me once in a while, but i keep telling him that i don't want him to because of my dad. i threatened him that i would tell, i told him i have a boyfriend i love to death, and i begged him to stop nicely. he still didn't get it. but then for a while he stopped and the other day he call my house and asked for me when i answered the phone. when he told me it was him i hung up. then a texted one of my friends so she could tell him not to email or call me. but when she called this morning, she said that he told me to call him. what am i going to do. i need that answer by june 4th-6th or if possible early as today. thanx for any help.