Stupid or what!!

Today I did a bit of shopping in M And S, amongst other items I purchased these flowers, as they were dripping over my shopping and I was now in the vegetable section I secured a bag, used for said vegetables around the base of the stems. When I got to the check out I was told I had to pay 5 p for this bag but I could get a flower bag free! No thank you I said, the cashier then told me she would have to remove this veg bag, by then it was screwed up and split as she removed it. Excuse me I said what will happen to that bag now? Oh I shall throw it away I was told , what has happened to common sense I ask myself!!