SEPHORA Sephora arbitrarily refuses to take their own gift card! Internet

     I was given a gift card from Sephora by an elderly relative. I tried to use it online at www.sephora.com. It was rejected. I called the gift card services number and found out that it had plenty of funds on it. I called Sephora and was told that if the gift card was bought on Ebay, they will not honor it.
     They did not say it was, but "if" it was. Talk about a bad experience! The customer service representative wanted the person who gave me the gift card to tell them exactly where it was purchased. Turns out the relative had the gift card for a long time and was unable to remember exactly where they got it. The woman is 87 years old and it was given to her at some point and she was just not able to remember when or who gave it to her. So we ran into a brick wall.
     Sephora can just arbitrarily decide they don't want to honor one of their own gift cards? What an abuse of power! So now I have a $150 gift card that has value but I can't use? What a miserable company!