EXCHANGE REFUSED

My brother who resides in Upington bought his daughter who stays with me in Nelspruit clothes using his store account. He sent the clothes through courier. One of the items bought doesnt fit my niece, and so today, I went to exhange the item for a bigger one at Truworths Riverside Mall. The exchange was refused as they wanted the account holder present. But how is he going to be present at Riverside Mall since he leaves in Upington, and now what am i supposed to do with the item that doesnt fit my niece since i cannot exhanges. Note that i was exhanging this for the same exact item, same price, the only different thing was the size. Truworths my just enlighten me on what im supposed to do with this item since my niece cant wear it!