If you've redownloaded the files since the update (you should have 2.5 somewhere in the file name), you definitely do have the new content! The new chapter continues directly off the first one, so try loading a save from Francesco's route or playing through it (the skip button can get you through content you've already seen very quickly, if you need to replay stuff).
If you don't have the 2.5 version, you can go to the Obscura main page and there should be a bar at the top of the page telling you that you've already bought the game. The download button will take you to the download page, of course, where you should have access to the newest files.