Got an overpayment notice, what now? (Tucson)

The agency says I reported earnings incorrectly, but I think I followed the instructions. I have been trying to stay organised about it. I did not notice any errors at the time. Has anyone disputed one of these?

Read the letter for the appeal deadline and act on it, even if you think you will end up repaying. Then ask about a payment plan.

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.