Got an overpayment notice, what now? - 26 weeks in

After 26 weeks of benefits I got a notice saying I must repay some of it. There are 10 people counting on me, so I am trying to be careful. I cannot afford to repay it all at once. 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.