What do I say about why I left my last job?

I have an interview next week and I am unsure how to explain why I left my last job as a warehouse supervisor. I worked as a warehouse supervisor before this. I do not want to blame the company. What do you say?

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.