This is just a suggestion, I don't know if it will work.
Do you know anyone who will loan you an Android based device who would loan it to you long enough to play for a few minutes? If so:
Log out of your game.
Un-install the game from your iPad.
Restart your iPad.
If you have your iPad linked to an iTunes program on a computer, delete it from iTunes on the computer.
Install the game on the Android device. Don't touch the screen other than to enter your age and agree to the license until all the updates finish downloading.
Log in to your game and play for a few minutes, making sure to go back and forth to Krustyland or your Neighborhood.
Log out of the game.
Clear the game cache.
Un-install the game from the Android Device.
Restart the Android device.
Install the game on your iPad, once again: Don't touch the screen other than to enter your age and agree to the license until all the updates finish downloading.
Log into the game and see if you can buy donuts.
I'm playing 2 games. 1 on an iPad, the other on Android. I actually started the iPad game by accident trying to transfer my Android game to a borrowed iPad so I could use up some iTunes credit I was gifted with years before (I put $15 to $20 iTunes gift card on my wish list and got almost $100 worth - most of which I never used).
I had to fiddle around like this again last year when I wanted to spend some Google Play credit on my iPad game.
