Dress malfunction on wedding day

I rented a dress from Eurobride, and even though their service was good, the dress was of really poor quality. Firstly, the dress I fitted one month before the wedding wasn't the same dress I fitted initially. It was the same style, but some of the smaller details differed and looked far more worn than the dress I was given to fit the first time. I decided not to make a fuss about it since it was still beautiful. On my wedding day, however, the dress' boning started bending and twisting every time I sat down, and by the time we had our opening dance, it looked like I've grown a few extra hip bones and ribs. I am very unhappy with the quality of the dress, and feel it did not match the company's professional appearance and the price paid for it.