Staff not proud of their work or the company they are working for

I was in Ackermans Mandela Park shopping center in Phuthaditjhaba Qwaqwa, worst customer service I received there, the cashier asked if I want a plastic bag then I asked if he's selling it or not the response that I got gave an impression that the cashier isn't Ackermans brand ambassador as he denied him selling it but Ackermans co is selling it meaning that himself isn't presenting the company as an employee. He took it personally as if I was asking if he's selling it obviously he cannot be at work and not be representing his company that's feeding him/ his family.