Selling rotten pies

On Sunday 3rd Dec 2017 I bought 4 pies which were off when I took them back the supervisor said I shouldn't have taken these one's I should have taken the ones on the bakery side.What I don't understand is that they are aware of the situation but they continue selling these pies to the public obviously not everyone is gonna benefit the shop will.How many things are they selling to people which are of bad quality.