Overpayment letter from the unemployment office after 15 years as a security officer

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

Keep everything in writing and save the confirmation numbers. It saved me later.

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.