How do I find out if there is a retail theft on my record and how can I stop my past employer from telling future employers?

I used to work for a retail store in the area. I was a seasonal employee who was let go because the position I was filling for was being returned. Upon my leaving, I was given no paper work. I have recently applied for employment elsewhere in retail. Everywhere I apply to either won't call me back or I can't make it past the interview. The last one in particular told me she liked me a lot but cannot hire me because my previous employer fired me for retail theft. There was no police were called, no police report, and no termination papers! I need help to try and figure out how to get this off of my record. Where would I look? Who would I call? Someone else said it’s just a bad recommendation. But if that's true, what can I do there? I don't even list this company on my job history. I'm just a lost girl with tons of potential looking for help.