Damaged Goods

I bought a pair of CAT sneakers size 9 and realised later, the same day that one of them was damaged. Returned them the following day, I took another box of size 9 to exchange with the damaged ones, only to find out at the teller that they were not even size 9 they were actually size 8 because all of their boxes were labelled size 9. I asked for a refund and was told by the cashier that they can only give a gift-card to the value of R1199. I have been looking at other Stores close to where I live, I cannot find the shoe. I do not have an account with edgars, all I wanted was a shoe. and now I am stuck with a gift-card that can only buy from edgars while I used my debit card to pay for the shoe.