exchange declined

yesterday i bought a hat at mimosa,so today wanted to exchange at foschini Bloem plaza,the other lady i think its manager at bloem plaza told me that i cant exchange my hat because she doesnt have space for the hat i should return it to where i bought it,my question is cant i return products anywhere in the country as long as i have the receipt and the tags?im really disappointed its not good business,now im stuck with the hat i dont want anymore