Help with this friend situation. plz?

There is this guy that I love and care about. I only love him as friends so I won't like to go out with him or anything. Anyways, for two weeks now, he has been ignoring me everytime I talk to him on Msn. I don't know what I did but I am feeling really bad. I have tried to talk to him about it but I got no reply and everytime I call his phone, he doesn't pick up. I am feeling so dejected right now. He is like a brother to me and I hate not talking to him. Please help what should I do?