ios 10.3.4: No internet access on iphone 5
I've made the update via itunes and installed the ios 10.3.4. I've did my backup to proceed to restoring the phone, but a message pops out saying I have disable Find my Iphone.
I can't obviously turn it off from my phone since I have no internet access and I tured it off via icloud.com. Unfortunately the issue remains since itunes keeps popping me the same message when trying to restore.
What should I do to get my phone back?
iPhone 5, iOS 10