I had a place I applied when I was going to college, they as well said that they "Lost" my application, and that I should fill out another one. What I realized is that they didn't want to hire someone who was as fickle with their hours/not clear about the hours as I had been. I went back, filled out another application, and when I got to the section asking when I could work, that little spreadsheet w/ the 7 days of the week

I just wrote open in big letters across it
Maybe try filling in "anytime I don't have class" and see if that helps
