bricked unlocked iphone 5

i got a brand new unlocked iphone 5... i opened, turned it on, set up everything but i didnt connect the phone to itunes, so... the phone was NOT activated... i put the sim card then it couldnt get any signal... so i decided to restore the phone using itunes.. i download the file, then it tries to restore it.. and then says

cant restore unwknown error -1

i activated 2 more iphone 5 without problems using the same computer (this time i did connected it to itunes, and was so simple to activate it)

but this other phone is now bricked, shows the "connect to itunes" on screen, but when i try to restore via itunes, never finishes... always shows error then im back at the beginning...

any ideas? help please