Vintage Closet of Kamali - Defective product Exchange not available

I ordered a dress from @vintageclosetofkamali through Instagram. I am regular customer there and I have been buying several dresses for myself and my family. However one of the dresses I bought for myself did not fit me. But I buy the same size always. When I asked them about it, they said it is because of an extra lining and that I should have bought a size bigger. But I was not informed about it during the purchase. I reasoned with them this issue again and again over the period of one week. They kept circling back to the same thing again and again, that I should have bought one size bigger. They also forwarded an old message that mentions something about extra lining, as proof that they had informed me. But this said message was sent to me * weeks after I had placed the order. I pointed it to them, but again, no response to that. This incident showed me the issue behind many such small businesses in Instagram. There is no way for someone to post an honest review about their experience. The page controls everything and they post only the five star reviews on their stories. People could easily get misled by it. Moreover, even if the mistake is on them, they can be adamant about not justifying the customer and still get away with it, because no one will know about it. One shocking thing is, This page has more than ****** followers. They will keep doing this to more people with the help of influencer marketing. I used to believe that more people should support small businesses. But now, I’m questioning myself whether I should stick to bigger brands.