Selling rotten goods

I am at Pick n pay Lemon tree and I was advised that I should come back for another maize meal and I told them I no longer want Pride because I ate maggots and their RUDE manager CHRISTIE advised me that I should call the supply , I bought this maize meal to you and I don't have any relationship with PRIDE , as pnp you are their client and should raised it with them, I ate that maize meal twice and I can sue this shop and take this to tweeter for selling rotten goods and the disrespect your manager has towards customers, I am really going to take this to NCC or consumer goods and services ombud