Pick & Pay bad service

My wife bought potato salad at Glengarry Pick & Pay at around 16h15. She added some mayonnaise and egg.when we wanted to eat, the potato is rock hard. Raw. We wasted the mayonnaise and eggs. I took it back to the shop and the guy I complained to just gave my money back after saying sorry twice. I then found a manager on the floor which also said sorry. She then went to check the salad and agreed that it is completely hard. When I left the shop she brought me a pack of potato salad for free. When we opened it at home, it was better, but tasteless. No more salads from Pick and Pay.