Google contacts party deleted, how to restore? My phone has since this morning forgotten about a part of my contacts: it only displays some of them in my contact list, or only displays their email address and not their phone number. I don't know what triggered this and there doesn't seem to be a logic behind it: I see and don't see contacts related to different accounts. 

Now luckily my WhatAapp conversations with many of the deleted people are still there, so I can re-add them to my contact list manually, but this of course doesn't work for people that I have not talked to on WhatsApp recently. 

The thing is, in my phone, contact sync with my main Google account is turned off (has to do with my limited data plan). This means that I sometimes sync manually, but I had some contacts in my phone that weren't synced with Google and part of them are now gone. Is there any way to restore these?

Also, which of the following will syncing my Google contacts do?


Overwrite the contacts in my phone
Add to my phone the contacts that are in my Google account without deleting any contacts in my phone that are not in my Google account
Delete all contacts that are just stored on my phone and not in my Google account? 


Any other suggestions are also appreciated, but please be very clear because I'm new to this.
If you sync your google contacts it will add the contacts present in your google account to your phone, without deleting or modifying the other contacts (option b).

The reason might be that, you accidentally deleted all the contacts in your phone and restored the partially synced contacts from your google account.

How to restore? - I think you already restored the available contacts using your google account. You can't restore beyond those contacts, unless you had the other backup source (like you can backup your contacts using inbuilt option for contacts backup)