I have a counterexample to this story. I was once paid an extra £20k pounds by the NHS. I promptly contacted payroll, but just got canned responses. This conti

I have a counterexample to this story. I was once paid an extra £20k pounds by the NHS. I promptly contacted payroll, but just got canned responses. This continued for another 2 months, with me sending repeated emails informing of the mistake. The overpayments stopped eventually, but my constant emails trying to arrange a repayment continued for 1 year. I even went to payroll in person, and they basically asked me to go back home and send a letter. The whole thing ended abruptly when I sent a "final" email to inform them my contract was coming to an end, and most likely I would be leaving the country after that. I promptly received a letter from payroll saying in angry red letters something along the lines of: "IT HAS COME TO OUR ATTENTION THAT YOU OWE THE NHS MONEY. IF YOU DO NOT MAKE ARRANGEMENTS TO PAY WITHIN 14 DAYS PROCEEDINGS WILL BE STARTED AGAINST YOU". So after one year of pestering them to get their act together, they gave me 14 days to arrange payment. Great. At least this letter meant someone finally opened a formal case, which meant there was now an actual human assigned to the case who I could arrange payment with. Since the money had temporarily put me at a higher tax bracket, I lost money from tax after repayment. I then spent another 2 years dealing with HMRC Tax Office applying for a refund. I managed to claim some, but not all the extra tax. In the end this whole incompetence parade cost me personally about £1k (not including time and money wasted chasing this up).