To the OP: you CAN get a refund. Just address it to Google Play (or Apple if you used to play the game on iOS) and explain what happened (but do please use punctuation marks) and you'll likely get a refund. I played the game on both Android and iOS and had done in-app purchases on both that were not as expected (lunchbox rewards not being added to my game on Android, permanent crash on iOS,...) and got a refund both times. If something you purchased does not work as advertised, then you request a refund.
To the others:
If your .sav files are larger than 0KB, try these steps:
Sad to hear it didn't work!
I'm afraid I have no other ideas, I fear you'll need to wait until someone else has found a solution or until they patch the game.
EDIT: according to user BrokenHaiku, he/she had a similar problem (in iOS though, but it might work on Android too) and he/she solved it like this:
Even though it didn't work I still learned a lot. So thanks for the help!