I'm afraid it seems that your upgrade was cancelled before it was finished. If you cancel an upgrade, you will get a pop up that asks you to confirm the cancellation and informs you that you will get half the cost of the upgrade back.

I am very sorry, but we cannot offer refunds for cancelled upgrades, or undo the cancellation itself. If you can't remember cancelling the upgrade yourself, please check if someone close to you, like a friend or a family member, has had access to your game. Sometimes accidental cancellations happen if the player has stopped playing, but the game keeps running and the player has not locked the screen.

I understand how frustrating this situation must be for you. If I can be of any further assistance, please do not hesitate to let me know.

Clash on!