Overpayment letter from the unemployment office, electrician's helper here

I received a letter saying I was overpaid about $650 on my claim. I have read a lot of threads here and could not find my exact situation. 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.

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