Bad customer service

I went to exchange for a bigger size and I was told they need the account holder even though I had the store card and id for verification they didn't allow me to. I asked them to keep it aside so that the card holder can come and exchange they said no they don't do set aside and the item was the last size. I'm so disappointed with their process and it's not benefiting us as customers. I went to Mr Price Mall of Tembisa.