You know, I never understood why people get so huffy in the checkout lines at Walmart LOL They'll happily spend an hour or two (or longer!) walking around the place, but heaven forbid they have to wait 10 minutes in line. Geesh.
I wouldn't let impatient people get to you, it's not your fault the employees are dingbats. (this is coming from a former walmart employee LOL but I worked there out of necessity not desire)
I say call corp or the store manager or even the district manager if need be. The problems can't be fixed if none of the higher ups know what's going on!