Wanted to do exchange they refused

I got a watch as a birthday gift but I didn't like the gold so I went to sterns Sammy marks and found two girls and I explained that I want to do exchange but I don't have a receipt cause its a gift the pregnant lady rep**** me with attitude saying I must tell the person who bought to come to the store and do exchange how can I tell a person who brought me a gift that I don't like what he bought.I told that Lady to do it as unwanted gift she rep**** with attitude and say I must go and look for a slip even now am sitting with a watch that I don't love cause they refused