I think I’ve told this story before in my old account or maybe on another subreddit, but it’s woth repeating.
I used to work taking inbound calls for a bank.
Me: Your’s truly
(After the usual greeting)
Me: How may I help you Mr Customer?
C: So I’m calling because I received my credit card statement claiming I owe you $256. I know that from I purchased *item* from *store*. I returned it, so I shouldn’t owe anything right? Did the store refund my money?
I gave him my usual script of how I understood his concern and I was going to review the account to see what was going on. I asked for the usual information to verify him and checked the account.
Me: Thank you so much for waiting Mr Customer. I was reviewing your account and I can see that indeed *store* made a refund to your account on *date*.
C: Then why I still owe $256?
Me: What happened sir is that you had a balance of $512, since the store refunded $256, you still have a balance of $256.
C: Why? The store refunded that, I shouldn’t have to pay for that.
Me: Sir, you had a balance of $512, minus the $256 of the refund, you still have a balance of the remaining $256.
C: Minus the $256 that’s 0, right?
Rise, rinse repeat for about 15 minutes.
I even read his transactions one by one and encourage him to do the math himself with me, to show him it added to $512, minus the $256 refund he still owes $256.
At the end he decided he wanted to be transfered to the dispute department because he thought the store was robbing him. At least he was not rude about it, jut incredibly stubborn and dense.