I was full of eneger at 114, and try to do a mission that cost 25, I was able to do it two times, and i was at 14... lost 50.... the page was not refreshing and i had to click more thant two click...

if you click it more, it will count every click the game recieves. so if your internet is being slow and you click it 10 times, quite possibly more than 2 will be registered by the game, acting as if you did the mission that many times.