Because this size is rarely found in physical department stores, your best options are specialized online retailers and "petite" lingerie brands.
Yes, you can buy a , though it is considered a "rare" or hard-to-find size because many mainstream brands do not stock bands below 30. A 28C is designed for an underbust measurement of approximately 27–28 inches and a bust measurement of 30–31 inches. Where to Buy 28C Bras can i buy a 28c bra