can't sign out of my icloud account.
I have an iphone 5s running ios 10.1(14B72) now the main issue is I cant sign out of my icloud account on this device cuz I wanna sell it, if trying sign out an error prompt saying "Verification failed" there was an error connecting to icloud server. Have tried to hard reset, network reset, as I saw in some posts but nothing helped so far, and the worst thing is that the phone indicates that there is an update of 10.2 but the link of 'Download and install' below the summary of ios 10.2 is disabled while the phone is connected to WI-FI, means I cant upgrade my ios even If I wanted to😠😠!!, help please am so confused right now don't know what else to do and sorry for the long post but I'm just getting tired with this, really tired.😕😕😕
iPhone 5s, iOS 10.1, I am from Tanzania ,East Africa