Game resets and all progress and purchases are lost

So this has happened several times to me now. I play the game, unlock things even make purchases and then all of a sudden the game will just reset back to square 1. But this last time was the best because somehow I still had a save game from the second to last level on adventure 2. So when I loaded up the save I finished the level with my 9 seed slots and some of the special plants you can buy eg double sunflower. and then when I came out back to the main menu the shop and everything had opened back up but all my purchases and been cleared again and my zen garden is gone yet again and I've lost real life purchases of coins