Refund Refusal

I bought my daughter a pair of tekkies. The tekkies does not fit and the branch does not have the size I need, they say that they can order it for me but then I have to pay an additional R114 over and above the R499 I have already paid for the shoes. I am not willing and cant afford to pay the additional R114 and I cannot wait another 2 weeks for the shoes to arrive. I have to go and buy shoes elsewhere, however they are now refusing to refund me. They say they can give me gift vouchers, but I do not want the vouchers. I need the money back so I can buy shoes elsewhere.