Unused iPod nano screen pops out.

Hello Apple Experts,

I would like to ask and also share if this happecned to you.

I have an iPod Nano 6th Gen whom i purchased around late 2011 to early 2012 (can remember exact month) that i used to wear it as a watch before. Fast forward to 2015, I seldom use my nano and been with my watch box since, the last time I wore it was last October 2015. Dec when I was checking my watch box and decided to wear the nano, i observed that something's off and the screen was out. It seems the battery exploded making the entire touch screen panel to pop out of the body.

Pictures below:

seems battery exploded inside

please do note that this was not overcharged, i always look at my watch box to get other watches before going out. The last time was charged was around late October 2015.

are there other similar such as mine? thanks