Overpayment letter from the unemployment office - 4 weeks in

I received a letter saying I was overpaid about $850 on my claim. It has been a long 4 weeks. I did not notice any errors at the time.

Collect your pay stubs and certification records for the weeks they name. Mine showed the error was a date mix-up.

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