how can you deal bonus electric damage?

i also have a bug at battle credits, i had 110 and now 75

1) To deal bonus electrical damage you must first deplete all of the enemies energy. Then after, any weapons that reduce energy (while the enemy is on 0 energy) will instead apply it as damage.

For example a weapon deals 30 damage (-40 energy depletion). This would instead dead 30 damage + 40 additional bonus energy damage, so 70 damage in total.

2) There have been complaints about this before, where the rewards from clans and achievements have been lost. I'll let someone know when I'm able to get on skype