Terrible service

On the 30th of November I bought shoprite brand Oats. When I get home. Decided to pour it in a container and am glad I did that. All to find out it's was rotten with worms inside moving around, on Sunday I took it back to the shop.when I got there the controller lady ask what is the problem, told her am returning the oats it rotten, she just looked me an said wait her, she come with a book asked for my details then refunded me. No apologize nothing as if nothing happened.