The only unlocking options for a iPhone 5... requesting an unlock from the originating wireless provider or a paid IEMI unlock purchased from somewhere on the Internet.
Chances are if you haven't fulfilled your contract, the unlock from your wireless provider won't be an option. So, the paid IEMI unlock would be the way to go... and is almost always permanent.
Unfortunately, per our Forum Rules, discussion of acquiring paid IEMI unlocks is not allowed for discussion here at iPhone Forums. However, you can check out ApplenBerry.com... they have IEMI unlocks available directly from their website. They're a fully trusted unlocking provider.