Dissatisfied customer

I bought sterling silver earrings,together with a couple of other sets of earrings,I only worn them once after being told by the manager that they don't loose color but i wore them and they turned black,basically they got damaged so I wanted a refund or exchange but I was told that the manager is around i must come back on Tuesday but I working late shift the whole coming week,I cant keep returning to the store,I have the receipt they emailed me,how do I deal with this situation?I bought the because I wanted to wear them at some event this weekend but that now defeats the whole purpose,to even think I always buy my accessories from you guys,I really find this to be very unfair,going to the store with a receipt and to be turned away when you can clearly see that its your products.my contact number is *** and ***