OP here. Yes, a letter would have been better, but I was scheduled for a shift that I couldn't make it to, due to having two jobs and time was of the essence. If I called off of my shift, I was afraid I would be fired. Furthermore, they would not let me find someone else to cover my shift, believe me, I tried. The shifts would not have coincided if either place would give me a schedule. But they wouldn't. Work was also closed, so I couldn't go in person to explain. I gave as much notice to my manager as I possibly could by calling. I had no contact information other than the store's phone number that I found online. At the time of the phone call, I was TRYING to give my 2 weeks notice but the manager hung up before I could. Oh well.