I would just keep calling eBay and asking to speak with supervisors until you get some assistance. What the seller is saying doesn't make any sense - why would she lose out on her sale? Let's just imagine that she did actually send the bag, and customs did actually flag it - what did they flag it for?? Devaluing it? She might get fined, and you might get charged a higher duty, BUT if she participated in devaluing the bag, why would eBay side with her if you both committed the fraud? ETA: AND if she knows they flagged, where's the tracking information or documentation showing that? Surely if she provided it, eBay would have it as part of the claim, no?