This wasn't a safety issue, it was an anti-carry issue. In which case, wrong department to be working in. I'd be more torqued off about the attitude more than anything. Pretty head stockboy with delusions of grandeur needs to reread his job description to think his $4.75 an hour includes telling anyone to take ANYTHING outside. Sure as hell wasn't something I dealt with in that position.
I'd like to know where in the Wallyworld training manual it says when dealing with a potentially beligerient (or in this case courteous person you don't feel like serving for a dumba$$ reason) customer you get in their face rather then dealing with path of least resistance and sending them on their way. Asking you to leave, fine. Calling the police, fine. Letting you stand there and not be served? Getting in your face about it? Where is that a good idea?