My sister is the Queen of Returns. No matter what anyone buys her she returns it for something else. She would get indignant if someone gave her a gift certificate though! There is an element of you cared enough to shop as opposed to just giving a gift certificate.
I told my sister that it would be easier just to get the gift certificate and get what she wants in the first place. I got "The Look" and just dropped the subject. I guess she just likes to shop! Go figure!
