Bad quality and service

I got married two months ago and bought my wedding ring from American Swiss. It was less than a month and the diamonds changed color. I was told that maybe I am allergic to sterling silver. So I took a credit and bought a 9ct gold ring from Sterns which also gave me trouble. The diamonds were dull in color. So I exchanged it to another 9ct ring. On that same day, I was showing my husband the ring and the bands, inside and out were badly scratched. It almost looked as if it was an used ring. So I got a credit and went back to American Swiss, chose another ring and after 2 weeks, that ring changed color. Once again, I've got another ring which is doing the same and it's only been a day since I do have it. I'm really disappointed at the fact that it's my 5th ring which is giving me trouble and I was told to do a blood test because the lady suggested that there's definitely a problem with me. But two weeks ago when I had taken my 4th ring, the lady made me try out a ring which was already changed in color and on display... So I guess it's the quality and not me!! I'm really frustrated because it's cost me a lof of money to keep exchanging rings all the time. Bad quality at American Swiss and Sterns Richards Bay !!!