My contacts, notes, and calendars on my iPhone all disappeared about a week ago, except for a few which look like contacts I have added directly on the phone.
It took me a bit to realize it, but once I did I tried syncing my iPhone to get the contacts, notes, and calendars back. This lead to the realization that my sync settings were messed up because iTunes started trying to backup my entire phone. Somehow the "Automatically Backup…" had moved from iCloud to This Computer, so I switched that back to iCloud. I'm the only person who has access to this computer or phone, so these settings changed on their own.
Once that sync with my Mac finished and the contacts, notes, and calendars were not restored I went looking and noticed that everything under iCloud syncing had been turned off on my phone, including Find My iPhone which is supposed to only be turned off if I enter my password. Again, I'm the only user and didn't change that so that was weird.
Turning contacts, notes, and calendars syncing back on under Settings > iCloud has not restored any contacts, notes, or calendars to my phone. I waited a couple hours to give it some time since it is set to check every hour. I have also tried turning on push and changing the time to 15 minutes. I even tried "manual" but couldn't find a button to push to do it manually.
I just tried turning off iCloud syncing and using iTunes to sync contacts, notes, and calendars manually. I tried twice, the first time just clicking sync all, and the second I selected "Replace information on this Phone". Neither resulted in any contacts, notes, or calendars on my phone.
Since I still have no contacts, notes, or calendars on my phone despite having iCloud contact syncing turned on both on my Mac and on my iPhone, is there a way to force the phone to do a fresh pull of the contacts, notes, and calendars from iCloud?
(Alternatively, have I missed something else that might be keeping iCloud from syncing the contacts, notes, and calendars.)
If it is helpful: I just noticed that my broswer tabs are syncing in both directions, Mac to iPhone and vice versa. So iCloud sync isn't completely borked.
Best Answer
Open Settings on your iPhone and find the iCloud settings page.
Find Contacts in the list, and switch it on.
If your contacts are still in iCloud, they will sync back to your iPhone.
Also check in System Preferences/iCloud on your Mac, and make sure those settings are correct, with contacts turned on.
Check your settings in iTunes, paying close attention to anything regarding "Contacts" under iTunes info tab
In the summary tab, you should have set things to sync to iCloud
Your info Contact settings should look like this: