system
A chat on subreddit /r/wallstreetbets
human
I overpaid a 401k loan once and when they refunded me the overpayment someone transposed a number and they paid me like $39 too much.  Then they froze my account and demanded I repay the $39 with a bank check.  I got annoyed because bank checks cost $2 to print, so when I sent the payment, just to be annoying, I demanded a $2 refund because it was their fuck-up. 
  
 I totally forgot I did it until 3 weeks later when I got a $2 check in the mail and an apology letter.

gpt
Wait, it probably cost them to send you that check  too. 
  
 Basically the bank win twice.