You should have use Internet Recovery to re-install the original OS.
iLife apps are part of the original OS, therefore when you re-install from Internet Recovery, you get the apps for FREE.
You just have to "accept" them from App Store.
Restoring iLife applications after Internet Restore of OS X :
If your computer came with OS X Lion or later and you erase your hard disk and install OS X, you can download iPhoto, iMovie, and GarageBand from the Mac App Store.
These applications are part of the software that came with your computer. Your account will not be charged for them
http://support.apple.com/kb/HT4718?viewlocale=en_US&locale=en_US