Latina Life black striped blazer 16 fits like 10

Latina Life black striped blazer floral lining marked as a size 16 but fits more like a 10 so here are the exact measurements: pit to pit 20.5" shoulder to shoulder 16.5" shoulder to hem 24" shoulder to cuff 24" pit to cuff 17.5" 63% Polyester, 33% Rayon, 4% spandex lining: 100% polyester