Explaining a layoff without sounding bitter - any advice?

I have an interview next week and I am unsure how to explain why I left my last job as a copywriter. I have read a lot of threads here and could not find my exact situation. I have been practising in the mirror. Do they ask follow-ups?

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.

Say it plainly and move on to what you can do. Interviewers usually move on if you do.