Hundreds of Contacts Erased from iPhone how to get back?

Contacts are synced with email accounts.

The missing contacts are undoubtedly linked to your gmail account. Make sure you have contact sync turned on for that account. If you're not able to sync with that account or you removed it from your device, that's why you're not seeing those contacts.

Serenitymcw wrote:

Oh I see I didn't realize that. Thank you. I deleted the accounts and readded them back to Gmail but not to mail yet. The contacts are in google and it is set to sync but isn't doing so. I'll try adding it to the iphone mail account also. It was giving me an issue yesterday asking for the passwords after they were set up already. Can the contacts be transferred from google?

So it was something you did actually. But you didn't know your contacts are tied to your Gmail account. If you add the Gmail account back to your email app, your contacts should still be there and resync to your iPhone.

I'm glad you got it sorted.