that's normal, if you read the basic rules and information in game. it only refills 500 energy and 50 stamina. try dealing with that when you have 450 stamina, and 1600 energy maximums!
This is not a bug. In Mob Wars: La Cosa Nostra you get a maximum of 500 Energy refilled for completing each level. For more details check out: http://apps.facebook.com/la_cosa_nostra/help -> Energy
i think i just said that that being said... why couldn't it be 500, plus a percentage of your total health? say 2 or 3%, times your level? a bit of extra math, perhaps, but it would be valuable to those who use more energy.
that's ok. i had questions about it at first, too never hurts to ask questions when you are learning something. and you never know-it may give the developers an idea for a change! here's my vote 500+ 2% of your total level!
To be fair to all users new and old, we decided to introduce Energy and Stamina Boosts as well as Daily Rewards instead of increasing the refill values.