No exchange but same store ???

My mom brought me a dress from the cornubia branch of which I loved only issue is it didn’t fit me the way I would’ve liked it too, so I decided to go exchange it at the branch in pinetown and to my surprise was told that I can’t exchange because of codes and what not but it’s the same store ? So I have to go all the way to mt edgecombe just to go exchange when there’s a branch nearby