Review on Sterling Silver Diamond Pendant Yellow Gold Plated Silver by Wayne Girard

Bought this pendant thought it was good based on the reviews. It looked fine, but I certainly didn't expect it to rust. I knew the band had changed color and could be cleaned to restore it, but this pendant is rusty which leads me to believe it is not 925 sterling silver. Tried to contact support but couldn't get through. They promise a 100% money back guarantee, but if you can't reach them, how can they deliver? Very disappointed.