Told I owe money back on my benefits - what worked for you?

The agency says I reported earnings incorrectly, but I think I followed the instructions. I do not usually post, so bear with me. The letter mentions an appeal window and a repayment plan. Who should I talk to first?

I asked for a waiver and a plan in the same call, and they gave me both forms. It was less scary than I expected.

Thanks for writing this out. I went through something close to it 10 months ago, and it got easier once I kept a simple log of every call and form.