Upload & Sell: Off
well it is buyer beware. Since the seller is talking I'd only be happy with a refund.
I'd be fine with a camera repaired to Nikon's satisfaction, though the seller wouldn't be unreasonable in balking if the camera was 100% fine (as far as she knew) when it left her possession. 1 day or not, who knows what happened to it? Unless you have a personal relationship with her, I think she's standing tall beyond normal.