OP sounds like a complete asshole.
This coming from a former 20 year old manager.
Areas of failure by OP.
1. Tried to road block the store from operating properly and hold other customers as collateral. So instead of calmly resolving the issue, you put the store's back against the wall and destabilize the situation further. Probably is rude to the cashier who tells her manager what an asshole the OP is so the manager is already on the defensive.
2. Instead of working with the 20 year old manager who might actually have cared and been smarter than the manager above him he immediately picks a fight with him too, so you have the cashier and the first level manager going to the 2nd level manager and stating what an asshole the op is. See where this is going?
3. Then he tells the first manager not to speak. LMFAO! First rule of management, you back your employees. At that point you had no chance in hell of winning, even corporate would have a hard time mediating this if you call them up. How the hell is the 2nd level manager going to know what is going on if he can't talk to his subordinates? And the 2nd level manager is immediately suspicious of you because usually people trying to commit fraud surpress info like that.
I normally dislike walmart because their customer service IS GARBAGE, but this time, I have sympathy for them.
Btw, I have been the cashier, the first level manager, and the second level manager and don't try pulling the "thats why you'll be in retail" holier than thou garbage on me since I have left retail, already have 1 degree, finishing another, and starting 2 more next fall.
Oh, also, I did some research and found that at least as of the 2001-2002 school year you were in high school which means you are at most 23/24 years old so it sounds even sillier to be talking smack about 20 year olds.