Told I owe money back on my benefits after 7 years as an IT help-desk technician

After 6 weeks of benefits I got a notice saying I must repay some of it. I am in Omaha, in case local advice matters. 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 made the follow-up calls so much easier.