Pathetic Customer service

Good day I'm currently at westgate mall todays date is 04/02/2019 I'm having a problem with an exchange without a till slip of items value of R2000.00 the items were bought at Somerset Mall yesterday On the 03/02/2019 I'm being assistant by cashier Naa- ilah she refused to do an exchange saying the transaction was not done in their store. I had to call customer care and was advised to speak with the store manager. I'm very disappointed with the service i have received before calling the store manager Mr Spencer.. please train the cashier properly so that your customer don't get to feel some type of a way as if I'm a *********.