They can also be refilled at the Bakery before the Pizza Window and pool bar opens. We"re members of the DVC at the bwv and my wifes complained before about the cup locations, they do not make a great effort to assist in soda stations especially with so many places on the boardwalk that you can purchase fountain drinks.
SORRY I FORGOT TO MENTION THE LAST TWO VISITS TO THE BOARDWALK POOL BAR. THE SODA CONSISTED OF THEM OPENING A CAN OF COKE AND POORING IT INTO HER CUP. JUST HOPING DISNEYS WATCHING T.Y. LOL