NWT Shane Justin Black Sequin Astros Dress Size M but it fits like a Small

My husband bought me this dress a few years back for an Astros championship party. It was a bit flashy for me but cool. Never wore but it runs small. I think it’s supposed to squish u in and BOY does it? There is a side hidden zipper but I had to just slide it over my head to get it on. Lol I was snatched tho when I tried it on. Size M fits like a S even XS but lots of stretch.