Got an overpayment notice, what now?, bank teller here

The agency says I reported earnings incorrectly, but I think I followed the instructions. There are 15 people counting on me, so I am trying to be careful. The letter mentions an appeal window and a repayment plan. Are payment plans possible?

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.