Disgusted in unprofessionalism

So I went for an exchange at identity in Somerset mall...3 times after I was struggling to exchange a gift for just a smaller size...the first time they send me back for a slip so the 2nd time I went back with the slip and they refused to help, the 3rd I went again just for an exchange and they were vulgar and rude with no professionalism,after sending me up and down 3 times with no consideration etc. this was a gift from a family member who does not live in any closehy radius and they insisted that I should present the card, why do you need a card,what do u want to do with someone else's card while it was a gift. Why can't I do a simple exchange for a smaller size. This is unacceptable and I was treated as if I was a ***** and as if I stole the jacket while having the slip. It is unprofessional and I'm disgusted in their customer service! I still have the jacket with no luck of an exchange for a smaller size