Unfair treatment

I need you help I bought a Shoe 23/12/2019 at Popup Europa art group in Eastgate.i didnt fit the shoe as they were closing, only to find out the shoe has a factory fault, then i went back the next day the shop was closed, because it was Christmas eve.. I went back they ask to send it back for repairs bt its now second time and the shoe still not fine..I ask them to credit back bt they refuse and ask to send 3rd time, I paid R790 fr a Shoe that must go to repair 3times now I stay far and i dont see any promise of getting help.. Pls help