Poor service

I made a purchase of Airforce sneaker on the 04-May-2020then when I got home i try it on to find out it was big, know i went to the store on the 07-May2020for a exchange the manager by the name Athdia refused, she says she can't take it back, i ask her do you expect me to pay R2000 for a sneaker that I'm not even going to wear, the sneaker still in good condition, this isn't fair at all please i need someone to intervention store is allocated at Cavendish Square