Got an overpayment notice, what now?

I received a letter saying I was overpaid about $350 on my claim. This is my first time dealing with any of this. I cannot afford to repay it all at once. Who should I talk to first?

If you are unsure, free legal aid in your area may help for this kind of notice.

Thanks for writing this out. I went through something close to it 11 months ago, and it settled down once I kept a simple log of every call and form.