defamation of character

Me and my friend was doing an exchange but we did not go to the counter together she went before me. When I went to the counter she went into the store to look for stuff to do the exchange.I was done before her then I heard the staff talking saying that the floor staff must watch the lady with the green bag and yellow t-shirt. I was shocked cause it was my friend discription thye were giving not comenting on their talk I just let it go.so when I spoke to my friend outside the shop to tell her what the people were saying she was so suprised and wanted to confront them so I said no cause I don't want to make a scene in the store. Why I'm bringing this to your attention is that thye must not judge a book by its cover and then so doing it infront of other customers it not ethical my friend is very upset about this and wants to take it further.