Adidas - Faulty shoes

Went to exchange the shoes that made my ancle bleed wich I believe to be factory fault however I was informed I can't return the shoes since the shoes where worn..Explained tat the only way I would know that the shoes are not in good condition is by wearing them..The shoes are still in good condition but they refused to exchange them for me..I won't be able to wear the shoes I spend R1500 because of their fault not mine.