Malabar Gold & Diamonds — 22k ring

I bought it last march 19 and it's color changed after 2 days. I took vacation in philippines and when i came back on the month of may i bring it in shop and they said that because i worn it beside my silver ring. And 22k is sensitive. They polished it but why now its side color fades again even if no silver ring beside. And no 1 week i'm wearing it again. Is it really authentic? Can u pls. Explain thnku.