Dis-chem refusing to return an item

I am n new mother. My baby is a week old. On Saturday the 9th of January I bought a breastfeeding bra from Dis-chem Rustenburg. I went home to fit the bra as Dis-chem don't have a fitting room. The bra did not fit it is to big. I went back on Tuesday to return the bra and they refused. I would appreciate it if Dis-chem can refund me as the bra is exspensive and nobody informed me that the item was not returnable, there is not even a sign up at the underwear section. And again they do not have fitting rooms so how are we supose to know if it will fit or not. <br> They also said I could have terurned it the same day but what is the difference between the same day and 2 days later, I just fitted it ones. <br> Please can I get feedback on this. It was highly unprofessional from Dis-chems side. I even returned a bra at Woolies that same day and they did not have an issue. Thank you.