Rusting Stanley cup

My best friend bought me a Stanley cup for my birthday last July. The Stanley cup started rusting February this year. I laid a complaint with my nearest store as it was bought online. I was asked to pay a R100 to go get it checked out. When it came back they had just given it a wash. The rust stain is still there. The cup is just a decorative piece of metal now in my home because drinking from something that is rusting is a health hazard. I’m so disappointed in Cape Union Mart what a way to ruin such a special gift. I thought the cup was a lifetime guarantee clearly not. It would’ve been better getting one from small street I guess.