This is a video guide about how to restore contacts lost on iOS 8 update from iPhone 5S/5C/5/4S. Here is the text guide http://www.any-data-recovery.com/iphone-data/top-3-ways-to-restore-iphone-contacts-after-ios-8-update.html
Good news: Tenorshare iPhone Data Recovery program now also supports to extract data from iCloud backup, that’s mean you are able to restore missing iPhone contacts on iOS 8 upgrade from iTunes backup, iCloud backup and without backup.
Moreover, if your iPad contacts disappeared too after updating to iOS 8, then another tool from Tenorshare also helps! Free trail iPad Data Recovery software here http://www.any-data-recovery.com/product/ipad-data-recovery.html