Ripped Off by EA!
You really should sync your game before quitting by visiting a friends town. So many people make threads like this and it all comes down to not syncing. It is poor design, I admit.
Forum Discussion
That doesn't sound right. EA should be able to see that you have purchased something with donuts, let alone see you bought donuts and randomly have them disappear. But like the others have said definitely sync your game, especially after making purchases.
