Expired food(cereal)

On the 20 October I went to Boksburg checkers and bought cereal for my son and he was so excited that I even gave him after buying it. The following morning after putting the cereal in the bowl I discovered that the cereal expired last month. I took it back to checkers and spoke to Mr Darrel or Darren Brown who according to me did not handle the matter well. He started to apologies with a bad attitude and I was not impressed. Instead of asking for my options he said come and get your refund. I believe that If I was not black he could have handled the matter differently. I was not aware that checkers sell expired food in the name of money not even thinking of my child's health. Food poising for example