I've just started to read this thread so this may have already been addressed. I had the same issue and lost 50 gems which annoyed me as I was trying hard to save them to get plutos dog house. Lets say I was a bit more mad than usual
badpc
so I sat down and sent a wordy email to the game masters. I told them they had disappeared from my gems and I was not a happy player. The responded by telling me how I had pushed a button to speed up a task so that was how I had spent them. Not loving their response, I replied with a thanks for telling me how I did it but now I know you don't have a failsafe in the game to prevent this from happening. I may have added that because of this their game sucked....
. I suggested they talk with their IT department and get that fixed.
They replied to my reply by saying so sorry, it has been suggested to IT and maybe (pfft, maybe) it will be fixed in the future. In the mean time, here are your gems back as a good will gesture.
I still make the mistake and lose gems sometimes, its due to going to fast when I hit the magics. Sometimes they don't collect the first time and I will re-hit them but to soon. My bad!
Long story short, you may want to contact them and see if they will do something to give you back the gems. Just a thought.....