How Can I Get Her Friendship Back ?

A few months back, I first met this girl, we only went out once but we still talked on a regular basis and still getting to know each other. But she moved away and things ended pretty badly between us mainly because I was surprised that she was leaving because I still wanted to get to know her and I knew that it wasn't going to happen but I didn't really know how to articulate how I felt about her. I mean I mean I liked what I did know about her and I would've liked to have stayed in touch but I wrote her an email that gave her the impression that I thought it was more than it really was and When I tried calling that weekend she was left I left her a voicemail message that sounded like I was upset. (I really was just distracted by someone fighting outside of my apartment), She got mad at me and didn't even want to talk to me or say goodbye even after explaining this to her.