I have a refund request on amazon, what do i do?

[jerrick]

I put up a phone about 2 weeks ago saying it was in brand new condition, I had opened it and used it for about a week so i thought it was still new (I know now that i was wrong). The customer wants refund because it didnt come with a battery, even though I got it like that from the cell phone store. I want to refund the money to him, but he says I have to refund it first before he even returns it. I called amazon and they said do not refund it until he returns it.He is threatening me though and saying he has talked to his lawyer and will bring me to a small claims court in CA. What do i do? I dont mind going to court but CA is so far away from me, and all over a stupid phone? Please help.