My guess is that the buyer has opened an item not received claim - they would have been expecting to receive the phone on Wednesday or Thursday last week.
How do you know they have been refunded?
Have you had an email from Ebay to say the buyer has opened a claim but they are dealing with it and you don't need to take any action?
"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)