Told I owe money back on my benefits - 7 months and counting

After 17 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?

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