Angry client

I went to Shoprite Phumulani mall on Saturday, and I bought a few things. Amongst those there were small 6 ultra Mels. When I got to where I live my kids opened 2 of those and they tasted sour. I live in Naturena and could not go back to Phumulani mall as it is in Tembisa. I was there for a family function. I took the ultra Mel and the slip to Shoprite Devland and they refused to help me saying I must take them back to where I bought them. how can I go back to Tembisa when I live in Naturena?