Got an overpayment notice, what now? (update)

After 18 weeks of benefits I got a notice saying I must repay some of it. I have read a lot of threads here and could not find my exact situation. 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.