Hi, 

I am so sorry for the delay in the response.

Are you still needing help?

Ok. If you didn't use them, did your game update, or did you uninstall the game and reinstall it?

Sometimes when games update or you uninstall etc, it can wipe boosters. Its totally not fair but unfortunately its because the boosters are saved on the device itself in the memory instead of in the game like on computer. So if you remove the game or sometimes the update wipes it briefly, that's why they go.

King recommends that you try not to save too many boosters so that they don't get lost