My boyfriend doesn't call me.. what should i do?

I have been going out with my boyfriend for 8 months know. Everything is great, except for the fact that he never calls when he says he will. I only get to see him on the weekends so its hard enough. Last week i didn't hear from him at all. He usually calls me on Fridays when hes down at his moms, but he didn't. Finally on Sunday he calls and can tell i was upset. He kept apologizing and said he was busy. Im thinking is he to busy to give me a call to say hey I'm not going to be ale to call you or see you this week because I'm busy. It takes 5 minutes. He doesn't have his own cell phone so i have no way to contact him. I have his moms number which is where he usually calls me, but that's it. Family, and friends are telling me that i should leave him. They don't like him and say that he lies. Which is true he tends to tell a lot of little lies. Idk what i should do, because when I'm with him I'm so happy. I cant see myself without him. Help! I really need some advice! Thanks:)