Shoes damaged in a day and could not be returned.

I bought a set of curse's shoes on the 11th October and on the 12th of October I call the shop to report the problem of the painful feet whilst wearing the shoes. The lady I spoke to said I should bring the shoes back, if I had worn them for a day. I kept them safely until I brought them today, with the slip but they could not be accepted back. The shop attendant complained about the condition of the shoe and that she could not resell the shoe. I had spent a lot of money from Trankei village about 250KM from EL to try and get a replacement. I am now so devastated, I am told that I cannot get a replacement. I trusted Green cross to offer me the right brand, since as a nurse I work for long hours standing, and I had to spend R1200 for this shoe just to be comfortable. I've now lost R1200, my valuable time coming to East London twice, money for travel. I'm frustrated instead of getting happines because of using a product of Green Cross. Please help me. Chwayita even mentioned that my foot does not match the shoe design, I don't know much about it, but I know that I had fitted the shoe initially, and when I wore it a work on Monday it was painful.