*sigh*
Unfortunately, you aren't the first this has happened to.
The file isn't saved locally, it's saved on a server, and it saves any time you change a deck/change something about your account. A win, the oracle, an upgrade, you name it.
However, it only /loads/ when you open the game.
When you opened your laptop up again, it re-saved your game. New saves over-ride old saves, regardless of changes in numbers, and your old data was lost.
You can e-mail zanz at help@elementsthegame.com, but no promises.
The obvious solution, not allowing a game to save if it has less wins/losses than an older file, has not been implemented yet. I have no idea if zanz plans to implement this in the future.
From now on though, close elements when you're done with it, and be very careful if using more than one computer.