I bought a MacBook for my wife a few weeks ago on Amazon, only to have the price drop a few days later. They wouldn't refund me the difference in price, so I went ahead and bought a new one at the lower price and returned the original one. I got my refund and that was that.

Fast forward to today, I saw another refund come through, this time for the second laptop. I contacted Amazon support and told them it looks like I was refunded for both laptops, and that the second refund was obviously a mistake, as I only returned one laptop and still had the other one in my possession. They acknowledged the mistake. He then said he talked to his supervisor and said I could just keep both refunds. I triple checked with him that it was ok and that he fully understood the situation, and he assured me it was fine, I wouldn't be charged down the road, and said that "your satisfaction is more important to me. We won't let our customer down at any situation. We are always here to help valuable customer like you."

Still not 100% sure I'm convinced they won't just charge me in a week when they realize the mistake, but for now feeling pretty good!