While, unfortunately, we're unable to directly return spent Goldmark, we do understand the frustration of tapping in the wrong place, or misclicking by accident, and losing some of your hard-earned currency.

In order to prevent incidents like this happening in future, all you need to do is head to your Settings menu and enable the 'Gold Confirmation' option. This will prompt a pop-up window to request that you confirm your spend request before it goes through.

I hope this clears things up for you, and I wish you luck in the field!