I would have said something to the management right then and there. I hope you called their corporate office with names and a description of the event. If for no other reason but self preservation, people need to do better jobs, with the way the economy is right now. Even if compassion isn't something they're familiar with, you'd think considering their paycheck might be motivational.

I'll admit, I haven't seen blatant disrespect like that from a Walmart employee before, but I can say that it's literally been about 15 years since I actually got GOOD customer service at Walmart.