1. The employees were "rushing" you because if they go over their shift, and happen to be fulltime associates, THEY GET IN TROUBLE!
2. WalMart wasted your time? How about the time that associate and her manager wasted ringing up items you knew you were going to refuse paying for?
3. Not every employee of a store as large as a WalMart Supercenter (or as small as a Rite Aid, et al) knows the price of location of EVERY item in said store.
4. Even management can't make employees stay past their shift, as per company policy, so the manager wasn't ever going to side with you anyway.
5. When you're rude, and people are tired and want to get home, what do you expect???