Wal*mart-Get Shot Down, Leave Angry

All day long my kids have been asking me to take them to Wal*mart to exchange some items. My oldest son bought a pair of walkie-talkies that will not stay charged. He, of course, did not save the receipt (he's 11) nor the packaging and bought them using a gift card. We went to customer service to see if we could exchange them. One employee told us that it was fine and we went to get another pair. They were out of stock. Here is an account of the worst customer service I have ever experienced:

Me: There aren't any more of these in stock. Can we get store credit instead?
Employee: No. (said in curt manner)
Me: Can we get a raincheck for when they come in?
Employee: No. There's nothing I can do. (said in very annoyed voice)
Me: Can you tell me when you will be getting more walkie-talkies?
Employee: The delivery truck comes every day and no one knows what's on it. There's nothing I can do. (said with a load of attitude)
Me: If I have the gift card that my son bought it with, can you look up the exchange using that?
Employee: No. There's nothing I can do. You will have to just keep coming in and checking to see if they are in stock. (said in slow deliberate voice, implying that she thinks I'm an idiot)
Me: All right, I guess that's what we'll do then.

That employee was so rude to me. I would understood if I was trying to return dirty underwear or something, but it was not something unreturnable. What I strongly dislike about Wal*mart is that they have nearly everything all in one place so I am pretty much forced to go there on occasion unless I want to drive an extra half hour to Selinsgrove. I try to avoid going there unless I absolutely have to.