Humiliating and embarrassing experience at Pick n Pay

My son purchased a 2 kg Basmati rice from the Pick n Pay Galleria Mall on Sunday at about 12:30 , what he didn’t know was that I had already purchased a 5 kg Basmati rice from Gorimas on Thursday. He bought the rice because he’s starting training again, so to make my life easier I poured the Pick and Pay rice into the bucket that I kept the Gorimas rice in, while pouring it in I found that it had weavels in it, it was about 4:15 in the afternoon so I called the Pick n Pay customer helpline and told the consultant what happened. She asked me for all the details, expiry dates etc which I did give her and told me that I can go back to the store for a refund, when I asked what do I do about the 5kg rice that has now also become infested with the weavels, she said she can’t do anything about that and that they are more than happy to replace the 2kg but not the 5 kg which only got infested due to their infested 2 kg. Today I went in to the store and asked for the manager on duty who happened to be Morne, I explained to him exactly what happened and asked him to check other packets if they also have weavels, we took 2 packet he opened 1 and there was nothing in there so he said he is only willing to give me the open packet that he had, which I refused. So in other words is like I am a complete cheap skate or a liter who made up an entire story of having weavels in their product to gain another 7 kg Basmati rice . I have never been so humiliated or embarrassed in all my life over weaver infested rice