Game deleted puzzle progress, help!

[fin]

Hey!

Been playing on and off, had about 300/800 done of a puzzle, and then when I tried to continue the game it had wiped out all progress. The board and all boxes were completely reset.

Is there any way I could undo that? I'm pretty sad, I worked at it for a while over a few weeks. I'm worried that it'll happen again so I haven't started a new game.

Please help!

sincerely,
fin