Got an overpayment notice, what now? after 18 years as a bank teller

After 14 weeks of benefits I got a notice saying I must repay some of it. I have been trying to stay organised about it. The letter mentions an appeal window and a repayment plan. Has anyone disputed one of these?

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.

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