I lost all my iPhone contacts after updating?

The last time I updated my iPhone I ended up losing all of my contacts! However I can still search for peoples names on my messages and my contacts name is there!
This obviously means that my contacts are still in the phones system, but for some strange reason they have disappeared from my contact list.

I still have all my photos and all my messages.
Any help will be great.

Call apple

Try uploading them back into your phone by iCloud or iTunes. If you've connected your iPhone to a computer lately, then they should be in either of those two.

Yes, No matter the data lost has been backed up or not, they are still stored in iphone database.
If have backed up your iphone, just restore from iphone backup with iTunes.
If not, the only way to get them back is to use the 3rd iphone recovery software to get them back.
Such as http://www.datarecoveryforiphone.com/ios-data-recovery.html

If it works, can you give me the best answer?