Geez, everyone's a expert and critic.

Regardless of right, wrong, maybe, whatever, her job is to cashier. Period. You have to email or call the company and complain. When I worked a second job as a sales clerk in a local major department store, a fellow employee got canned for criticizing a customer's taste in clothes. You're the consumer, you basically pay their salary so complain. Don't let those nitwits affect you. You do what's best for you and your situation.