Sweetheart Gown 2526

I recently purchased a Sweetheart Gown Style #2526 from a store. They said the size was 6 but in fact was a 10. They won`t give me a refund and the dress is to big. Please if anyone has this style brand new only please since mine is the same with tags I would love to trade. If someone on the other hand is looking for the same gown in a 10 I would be willing to sell it for $450.00 Please let me know, you can see a picture of the dress at www.gowns.com . It is an absolutely gorgeous dress and if it was not for the size I would not be placing this ad. Thanks in advance for your help.