Last Friday, a friend of mine asked me to accompany him to buy a new shirt at a department store. We left home at 03.00 p.m. by motorcycle. As soon as we arrived there, we went to the clothes section. I let him choose one. An hour later, I got bored watching him confused in choosing a shirt. So I left him and went to the cassette counter. Thirty minutes later, I went back to the clothes section but I couldn't find him there. My cell phone was broken so I couldn't call him. I went to the parking area. I saw his motorcycle was there but I couldn't find him. I waited for him for a few moments then finally I gave up and decided to go home.

    When I arrived home, my mother told me that my friend called. She said that he was in the department store looking for me. My mother asked me to come back to the department store. Reluctantly, I walked to the department store and you know what? When I arrived there his motorcycle was not in the parking area. He just went home. I was very tired. There was no other choice. I had to walk home again. When I arrived home, I was so tired. I was very angry but when I saw my friend's broad smile greet me in front of the door, I just could not help laughing

The writer couldn't contact his friend because ....