Have you asked the buyer to pay you and given them a way of doing so?
The buyer can't repay you through Ebay. If you both have Paypal, you can send them a Paypal payment request or you can provide details of your bank account so they can do a bank transfer.
The forum does not allow you to name other members so a moderator will probably remover your buyer's name from your post.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)