I know that many brides use David's bridal, and that this situation happened at only one store, but I thought I would share it with ya'll.
In an Orlando shop almost exactly 10 years ago, my sister walked into David's Bridal to pick up her dress... Which to her horror was "lost." They had no idea where her dress was. She sat in the middle of David's Bridal and cried her eyes out while my mother was in a frenzy. My mother told David's Bridal that they WOULD let my sister choose a new dress, whatever the cost, and they WOULD give it to her. Sure enough my sister found a dress she liked and David's Bridal followed through.
What a scary thought that a dress can be lost, huh? I am not sure what I would do if my dress disappeared. I think I love mine too much to pick a different one!