Need Confirmation Button for Spending Gold

Really frustrated - got 50 gold yesterday for achieving 2,500 points in the PVP and went onto 'energy' screen to use up an energy I had previously purchased with some gold - I accidentally hit purchase another 3 bars of energy for 20 gold!!
Surely there should be a 'are you sure?' message as I have now lost 20 of my hard earned gold that I was trying to save towards a new gun
Aarggghhhh!!!!