Ebay will deduct the refund from your linked bank account and then pass the buyer's payment to you.
This means you may be out of pocket for a short time.
Unless you have already cancelled, in fairness, I think you should give the buyer a few more days to get back to you.
It looks as if they only bought the item on 11th and they have paid showing they are a genuine buyer.
"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)