Now I know why I don't shop at Walmart very often.

I agree 100% with everything you said, but you put yourself on her level when you began arguing and cussing at her. The best thing to do would have been nothing and watch the little brats break their fool necks.
Best thing to do is what he did. Have enough do nothing to go around everywhere these days.
Time to stop it. You need to go to some folks level and lower if needed.