Genx South gate store

Hi

I have a problem with this store that we bought my 11 months baby girl clothes,we bought a two piece nike suit for R540 and the shop keeper never double checked the sizes when we collected the items,it was a one month laybuy also included was adidas shoes for R510. The size of the clothing is 3-6month's and my daughter is 11months. The name of the shop os GenX at South gate. They dont want to exchange their clothing,so now i just want my money back for the R540 apparel. I would also advise fellow South Africans not to shop at GenX. They are a *****. The *********** staff member called the *********** manager "zama" who was not there and declared that i wont exchange. My rights were violated buy this store and i will never shop there ***fly by night shop*** i want my money bac**** Kindly help us.