Unintended upgrade

Hello there, I don't know if this is the right forum for this problem but anyway.So, here is the thing, I had my copper smelters paused and i was distracted by something as i wanted to work them again, and lo and behold, i clicked the upgrade button instead for two of them before i realized what i did and stopped the clicking spree. So, since there is no 'cancel upgrade mechanism' i lost 1000 gold coins and 600 marbles.

I hope this can be fixed and thanks in advance.

Welcome to the Man's club.

Everyone does an Unintended Upgrade sooner or later. Part of life :)
Your first Crossbow loss will be the next big step up on the ladder!

I don't have an absolute advantage in making weapons mate, so gold is a better substitute. Anyways, it is possible to retain the same amount of gold through trade, only a matter of time.