Has the buyer been refunded?
If they don't use the label you provided, you won't be charged for it and you are not expected to refund until you get the item back.
Buyers do sometimes start return cases but then don't bother to complete the process.
"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)
