For quite a few years, the window for an app or game refund in the Play Store has been 15 minutes. Today, it looks like that’s changing to 2 hours, but just for games. There’s no announcement from Google, but Android Police ran some tests, and found that although 15 minutes is still listed as the official refund time, it took exactly 120 minutes for the button to disappear.
This could very well be a glitch, but we’ll wait for something official from Google to be sure.
Source: Android Police