software update failed and have error 1669

Hi there. I am trying to find a soloution as I tried to update my software (on a pretty new) iphone 5. The update failed and gave me an error 1669. I have tried to restore the phone on my brand new 1 week old imac with all the latest software but the phone still wont come out of recovery mode? This is very frustrating as I need the phone for my work. I have spent soooo much time trying to find an answer.

PLEASE HELP!!!!!!!!