That's so strange! I've purchased many things from this seller before and all of them have been NIB for me.
Perhaps it was a simple misunderstanding? I would contact the seller directly first. I've had a case where a product was listed as in good condition, but when I received the package, there was scratches all over. The seller gave me a 60%? refund for that product.
Usually sellers are VERY keen on feedback. They should be willing to help you, or you can always open a case with eBay and/or give negative feedback. I've heard that sellers always aim for 99.6% or greater. Seeing as this seller has a100% Feedback score (and several transactions!), you could assume that they want to create a good selling experience.
Try contacting them first and go from there!