How do I restore my iPhone from an iCloud backup?
When you restored your phone, did you do the configuration steps in iTunes or on the iPhone itself? Try restoring again, and follow the steps on the iPhone, not in iTunes. I've seen some reports claiming that iCloud restores can only be started from the device itself.
To see the setup assistant in a non-new phone, yo need to reset "all settings and data" from the iPhone, not from iTunes.