Black satin gown with crystal belt

I lost my black satin floor-length gown by Adrianna Papell, size 6, yesterday around 3pm. I was leaving a charity gala near The Shambles and York Minster area, wandering toward Coppergate Shopping Centre when I realized it wasn't on my arm anymore. The gown has a detachable crystal belt that catches the light, and there's a tiny snag on the left shoulder strap plus a faint wine stain on the inner lining. It means a lot to me—it was a gift from my grandmother—and I’d really appreciate getting it back if anyone found it.