Google officially expands Google Play Store refund window to two hours
To request a refund, you open the Google Play Store and go to My Apps. Select the game or app you wish to return, click on refund. Keep in mind that if the two hour refund window has expired, you will not see that option. If the two hour period has expired, you will be allowed to uninstall the app or game from your device, but without receiving your money back.
Google apparently increased the refund window to two hours, unofficially, last month. Now, it seems that Google has made it official. So go ahead and buy that expensive app or game. If you don't like it, you have two hours (120 minutes or 7200 seconds) to return it for a complete refund. Remember though, that you can only receive a refund on a particular game or app one time.
source: AndroidPolice via Gizmodo