Why my contacts have been deleted
This morning all my contacts had been deleted from my iPhone why did that happen and how can I get my contacts back on my phone.
iPhone 4S, iOS 6.0.1
Where do you backup your contacts?
If to iCloud, is there another device sharing your Apple iCloud ID? If there is, anything done to contacts by the other device will be synced to your iPhone contacts. The same is true of anything done to contacts by a computer on icloud.com. Go to icloud.com and check to see if your contacts are still there.
If you back them up to a computer through iTunes, then you can recover your contacts by re-syncing them from your computer to your iPhone.