This is most likely due to an issue with adjusting the clock on your device. One potential solution is to set your clock back to the original time, and then wait for your clock to catch back up to where it was last changed to. So for example, if you moved your clock ahead 2 hours, set it back to normal, and then wait 2 hours. You can also spend Gold to refill your energy and that will also fix this energy refilling issue. Please contact us directly  if you should require any additional assistance.