You are free to have this leak but bear in mind, it's not mine, so don't bother me if the links/program/source/whatever stop working. I take no responsibility of this, use at your own risk.
so basically you can buy the gems then follow the steps below and get a refund, but still have the gems left to use and p.s. refunding with google play, you should also be able to do this with other purchases from android play store or something. Oh yh and if it is like 1 month old the purchase it will still work as i did it with my order that was 1 month old.