If you can get the buyer to verify their correct address you could reship it to that address. Yes, you will pay a second shipping fee but that will be a whole less than having to refund the entire amount.
Others will warn you that if you so not ship to the address on the eBay/Paypal screen then you loose seller protection. I guess it comes down to how expensive an item it was. As it is now you are going to have to refund the whole amount. But if you reship it you are only out a small amount.
By the way, in cases like this I have asked the buyer to pay the reshipping costs because it was their mistake in the first place, That way you are not out anything.
"Laissez-faire capitalism (AKA The Great Material Continuum) is the only social system based on the recognition of individual rights and, therefore, the only system that bans force from social relationships." ~ Ayn Rand
