Unfair service at Jet tfg.

My wife bought underwear for me at jet pretoria centre walk. Before they knocked off. When I picked her up I told her I needed underwear from Markhams.. As they were sealed early in the morning I returned to the store for refund. They said they don't take underwear while they still sealed. Receipt is there n they still packed. Not opened. So now m forced to have something that I don't like. They still sealed even today. With receipt. They told me to read at the back of receipt but I tried to tell them that this things are sealed.