Bad customer service

Good Afternoon I am writing this to lay a complaint in the violation of my rights under the provisions of the Consumer Protection Act.On the 1st of October 2024, I sent my daughter to go purchase full cream diary product and she mistakenly bought Full Cream Milk and when I returned the item at the supervisor ,I was mistreated and given a bad attitude when I enquired and requested to exchange as the product was not yet opened. The supervisor ean employee at PnP Qualisave Protea Boulevard refused to exchange the item I had purchase with proof of purchase and when I asked her where does it stipulates in their policy that a customer is forbidden a dairy product purchased just minutes before it would be exchanged and she herself couldn't find the policy and she requested her colleague/Supervisor by the name of Chermaine to bring some piece of paper printed from the head Office and even the Slip itself does not say anything about returns of dairy products.I did not even go home with the product nor opened it and yet they had the audacity to tell me that according to their policy, after 7 minutes of purchase, I am not allowed to return products.I still fail to understand how their protocol can only be at their office while as a customer I do not know anything about it because now what infuriates me is the fact that I already have milk and I can't exchange what I initially intended to purchase. Please intervene in this case as I'm severely dissatisfied with the poor customer service and treatment I received from that store.