Unfortunately, The Behemoth is absolutely unable to restore any lost Castle Crashers data. Unfortunately, save data is not stored or handled by The Behemoth or Microsoft, and cannot be recovered.
We can, however, give you some tips on how to keep this from happening in the future.
Our guess is this happened when you pressed the 'X' button on the player statistics screen, which is Castle Crasher's reset button. We put this option in Castle Crashers specifically because our fans requested the ability to reset progress -- so please, please be careful on this screen.
If you think you lost data for a different reason, though, let us know! We still won't be able to restore your progress, but we'd like to look into your issue further so we can keep it happening to anyone else.