If your calendar wasn't synced with some cloud account then it was probably just stored internally to the Simple Calendar app. Dr Fone probably doesn't have access to that, and is unlikely to know about a specific calendar app. If it says it can do calendar backups it probably does it by acting as a calendar app in order to access synced calendar accounts, which won't help with an unsynced calendar that's stored by a particular app.
It's similar with SMS: things like SMS and Contacts are stored in databases that are designed to be accessed by different apps (e.g. any message app, any contacts manager), which means that a backup app can access them in the same way. But backing up the data of other apps requires access to them. For security reasons one user-installed app cannot usually access another app's internal data. On a rooted device you can allow a backup app to have that access. Otherwise you can use USB debugging to back up (this is how the Helium backup app works). Those are the only 2 ways I know, and I don't know what Dr Fone does.
For general app backups on unrooted devices Helium is the app I've used with most success, but it does require a little fiddling to set it up. Even then it won't get absolutely everything, and you need to back up the USB-accessible part of the internal storage separately. I personally prefer to use a separate SMS backup anyway (e.g. SMS Backup & Restore), since I know those apps allow you to transfer the backup to another phone and restore there (I've done it many times), and am more comfortable sticking with what I know works.
