Hero's skill was changed

I recruited a hero from the tavern with the name of Deborah. She was a mage, and had the skill Heart of Darkness when I recruited her.
I paid 800k credits to open up 3 additional rune slots for her, and put her in my formation.
The next day, her skill was changed to Hammer of Darkness. This was a total waste to me, as I already have Catherine with the same skill.
Please change Deborah back to Heart of Darkness. If that can't be done, can my wasted credits be returned to me?

I'm afraid all white mages were patched so they had the Hammer of Darkness skill rather than Heart. The only magi that's supposed to have it is Shayd, a gold hero. You won't get your Mage reverted back to Heart.

I have similar thing happened to me..Name: Bamboo from server 10 scales of ice dragon...hired white mage cuz she got heart of darkness skill then 1 day just change to hammer of darkness skill..what a waste of blue medals( i bought with gems) and credits to open extra rune slots..can i get back my blue medals and credits?..Mage name is Odellia..up to 5 stars lol