Fiancé got scammed on engagement ring? Venting

My fiancé got me a 1.00 carat solitaire engagement ring. It catches the light really nicely and seems to be a really nice quality ring. One day I was looking closely at my ring (months after he gave it to me) and I saw a black spot near the edge of the diamond! I asked him if he knew that the diamond had visible spots and he said no. He finally sent me a picture of the paperwork he got for the diamond and The diamond was graded by the EGL as ideal cut and SI3 quality. I had never even heard of SI3 quality before and when I googled it there are so many sites that say the SI3 grade is fake and a huge scam for jewelers to sell I1 diamonds off as better quality than they are. We were going to go back and look for bands at the same store but now I feel like they are a horrible company tricking consumers. I had told the lady that we’d come in to look at the bands but now I want to call back and complain about their tricky business practices but I know it’s probably not worthwhile. Sigh. Just venting.