Restoring iPhone contacts from backup immediately undoes itself By accident, I deleted most of my contacts on my iPhone. They were also on another device, and were deleted from that one as well when they were deleted off of the iPhone. I restored the iPhone from a backup and they appeared for a minute…then disappeared again. I tried to restore it from the backup again and the same thing happened.

How can I fix this?
It is possible that, after restore, you are syncing your iPhone with some source where the contacts have been deleted as well. If so, you will need to stop syncing and/or restore the contacts in that place as well.