Menlyn lovisa selling **** 925 Silver

I'm highly disappointed in lovisa Menlyn. I resently bought their sterling silver 925 earrings and a ring on the 3rd of October 2020 and it has started to rust so meaning they have given me a faulty product or they tired to rip me off because according to my knowledge 925 silver is not supposed to rust. Now they are telling me I can't get my money back meaning I'm losing the R230 and the R330 I bought these products with.