iPod and Apple Care

We had a 20 gig iPod that went bad over the summer and was replaced with another 20 gig iPod at the Apple Store in Bloomington, MN. This one started to have a sad face about a month ago. After trying everything, restore, etc. we sent it in to Apple Care. It came back saying that there was external damage to the case of the iPod that caused the sad face. There is nothing on the case of the iPod that shows external damage. Talking to Apple support they said to check the case of the iPod, that there is evidence that the case was pried open. Okay, so there is a slight bowing of the case at one point, but that wasn't anything that we did. My son wouldn't know how to pry the thing open. Also, it's interesting that this is discovered only when the thing went to Apple Care for refurbishing. Learn a lesson, never accept a refurbished iPod without first taking pictures, and don't send a product off to Apple Care without first taking video.