When making a purchase with gems in game, it always requires a two-step process to minimize accidental purchases. We followed this design principle throughout the game so that you are always aware which item you are interacting with before spending any actual gems. 

For example, when you purchase an item in Shop, you will need to first choose the item, and then in the context menu, you will need to tap the 'Get' button to confirm the purchase.

Since our game is multiplayer online game, in which real people interact with each other, reversing changes would have adverse effects on other players you've interacted with. 

As we can’t turn back someone’s progress in the game or remove features, providing a gem refund would provide your city or armies with something for free, which we see as unfair to other players who fought the battles with you, earned the same item or upgrade through their own gems or gameplay.