1940s Shirt Dress

I had really high hopes for this dress, but was very dissapointed. I’m 5’8, 180 pounds, a size 12 or a L usually in anything I buy. I purchased a size L (12/14) in this dress, and could not even get it buttoned up halfway. I had to check the size on the tag because this fit more like a 8/10. This dress runs very very small. Like I don’t even understand how I couldn’t get more than 2 buttons buttoned. Really bummed, as it was pretty pricey. Waiting to hear back on how I can exchange, will update.