Overpayment letter from the unemployment office - first time posting

After 26 weeks of benefits I got a notice saying I must repay some of it. Any experience at all would help. I cannot afford to repay it all at once. Has anyone disputed one of these?

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

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