Diva CatWalk Blue Margot Pencil Cocktail Dress

Diva Catwalk Margot Pencil UK10/US 6 Dress - NWT New with tags. First time ordering it, didn't fit. Please check measurements, seems to be more of a size 2 or 4, that's why listed as a size 4. Waist is where it seems to run small. Measurements: Length (shoulder to hem) 40 inches. Bust (underarm to underarm flat) 15 3/4 inches Waist 13 1/2 inches Wash and Care: Machine washable at 30 degrees. Non-creasing fabric Materials: 77% Polyster, 20% Rayon, 3% Spandex