DISCOLORING OF A RING!

My husband bought a ring for me at Sterns Eastrand mall, 2 weeks later I noticed that the ring is discoloring. My husband went back to the store to find out what can be done about this, the consultant advised they would have to speak to the supplier, which when we bought the ring we spoke to them not the supplier. The consultant also mentioned that that I had maybe app**** harsh lotion on my hands or washed my hands and it must've affected the ring. We were never advised to remove the ring when applying lotion or remove the ring when washing hands.