Poisonous Food from Southgate Checkers

I bought lasagne sheets at southgate checkers on the 12th July 2019,and my and I opened the box on the 13th trying to prepare for supper and only to find a worm and spider webs inside the lasagne box. It was not the first time we bought food that is off and the expiry date is far, so my question is, is checkers selling us rejects and food that is off? And after a few grocery purchases, that proved that checkers sells us rotten stuff. Our kids are not safe with this kind of products and they are endangered by this quality of food. I ha e decided that I am going to sue checkers at southgate for their poisonous products. My suspicion started when I realized that the product I bought is 500g and the purchase price was R39.99 and funny enough the 250g was on special for same price R39.99 which did not make sense but non the less, I thought it was a bargain, only to find that there is an issue with that product.