You thought only words can hurt people, but it hurts more when you don't speak a word

Recently I have this friend who cares about me and talks to me whenever I have problems. We don't usually contact with each other as we are in different places. We don't have many topics to say as I am not that kind of talkative person and he is a really cool one, to me. I don't usually tell him my problem but instead, he notices my status I posted FB and knows that I am not feeling good or what. He did something so sweet and heart-warming to me by calling me whenever I have problems. Yet, he is just my friend, an OLD FRIEND I can say. 

It's semester break now. He bought me chocolate from his Uni place. I'm pretty happy with it yet feel shameful for not buying him something. Well, KL has nothing good to buy, for him. When I get back from KL, I told him that I am back. He did not reply. The second day he replied and told me to contact him when I'm free. OK. When I am free, I contacted him again and he came and pass the chocolate to me without a single smile or HI. I tried to talk to him but he walked away. OK. This is not the first time he did this and it is really kinda hurt for me. I whatsapp-ed him but he did not reply or seen me.

I am writing this because I just don't understand why he is giving me this kind of attitude when we meet each other. It hurts whenever I think about how he's being so cold to me when we meet. =/