Worst customer experience ever?

Dunno if there's a thread that exists for this already, but whatever. Former (as of ten years ago) employee here. Had a customer come in once to buy a used game. Paid with one of those prepaid visa gift cards. I give him the whole spiel (power up membership, discount, reserving games, blah blah blah) and also mention the seven day return policy for used games. First time I had seen this customer, so didn't anticipate them being a policy abuser.

Fast forward about an hour or so, and the customer comes back to return the game. He asks for cash back. I explain that I can only refund it to the original form of payment, or put it on a gift card. He proceeds to begin screaming at me like I've never been screamed at before. He calls me an asshole, a little bitch, the whole nine yards. I'm attempting to calmly explain that I can't just give him cash, even though he looks like he's about to jump the counter to try and beat my ass. He then demands to speak to the store manager.

I call my SM (it was their day off) to explain the situation while the guy is screaming in my ear and into the phone receiver. My SM tells me to just give him the cash to shut them up. I go ahead and give him cash, and his demeanor immediately shifts.

He says, "And that's how it's done." He proceeds to explain that he used to be a general manager and "understands how retail works." He also tries to act like my best friend and tells me I need to not be so uptight about the rules and to just chill out. He then left the store without further incident.

I'm completely baffled by the entire situation. I'm so pissed I'm actually shaking. The GA I was working with that shift was completely speechless the entire time (no other customers came in during this entire interaction, so they were just behind the counter with me.)

Thankfully I never saw this customer again, and never had nearly as awful an interaction like this while at GameStop. It really seems like it's one of those places where people just feel free to be huge pieces of shit to employees because they know there's zero chance of consequences. Anyone else have as shitty (or a shittier) experience as an employee?