<prompt> Human: My apologies if this is the wrong sub, but I wasnt sure where else to go. Also, TL;DR at bottom.About three months ago, I took a handful of old U.S. govt savings bonds into my credit union to be redeemed. The combined face value was about 450, and I walked away with slightly more than 1,000. I hadnt previously calculated the value of these bonds but since they were all 15-20 years old, 1000 seemed about right.However I just received a call from my credit union that they had incorrectly processed my bonds and had actually overpaid me by 145. The lady on the phone very politely requested that I stop by the branch and repay the 145 that I owe them.Ethically, Im sure that I have an obligation to pay them back, and I probably will. However, in my field sales and marketing I would never request that a customer come back to me and pay to correct my mistake. In the name of customer service, I would have written off the loss assuming it wasnt too onerous a debt and take steps to make sure that the customer came back to me for more business in the future. Its probably wrong of me to feel this way, but Im a little upset that a financial institution with a few billion wants me to spend my own gas money to help them correct their mistake. Especially since I would not act in the same way.So my question to rpersonalfinance is: what should I do? Am I legally obligated to pay them back? Can I just ignore them? Negotiate with them? Thanks!TL;DR: 3 months ago my Credit Union overpaid my bonds by 145. Now they want their money back and I kind of want to give them the finger. Advice?  <response>: Pay them back. Yes, you are obligated to do so. 