Denied an exchange at sportscene

I went to Clearwater sportscene to do an exchange unfortunately the store manager could not assist,telling me I need to have a receipt for doing an exchange, cause I was not refunding , and the shoes are still new not worn or nothing it's a matter of a size being small , I even offered to buy 2 pairs even if it means making sure I buy for the exact amount of not more , and I'm desperate cause Wednesday it's Christmas I need shoes for my child , all because I did not have a receipt but it's their shoes and they worth R1699, and the consumer rights does state that I can exchange without a receipt...please assist