Phone design

The battery cover on my phone does not have the best design and fell off while we were walking through the airport.  I went back and tried to look for it but no luck. -  I figured it wasn't a huge deal as the phone still worked. 

I probably should have stored the phone on my pocket as the next day I lost the battery as we were rushing around.  Managed to find a Verizon store but still a pain to shell out $35 due to a poor design.