Your save is located in your Unity folder on your computer. go to C:\Users\yourusernamehere\AppData\Roaming\Unity\WebPlayerPrefs\chat_2ekongregate_2ecom and find your adventure capitalist save. Sort by date modified to make it easier to find. Back up that file and even if it's deleted you can restore it.
Until Adventure Capitalist bring back the export feature, you can manually back up your saves. To do this, go into: C:\Users\yourusernamehere\AppData\Roaming\Unity\WebPlayerPrefs\chat_2ekongregate_2ecom and find your adventure capitalist save. Sorting by date modified should help because the games name does not appear in the saves title. Simply copy the file and place it somewhere safe. If your progress is reset, place the file or a copy of it back in the folder.
The save files for the game are stored on the players computer, in the Unity folder. Deletion of these saves is most likely the reason people lose their save data. I recently went into the folder and deleted my save then restored it to test and my save was wiped until I restored the file from the recycle bin.