Overpayment letter from the unemployment office after 17 years as a machine operator

The agency says I reported earnings incorrectly, but I think I followed the instructions. The letter mentions an appeal window and a repayment plan. Has anyone disputed one of these?

If you are unsure, free legal aid in your area may help for this kind of notice.

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