07-12-2012 08:20:34 PM
07-13-2012 05:16:15 AM
You didn't give enough information so I am speculating here. If you are saying you "updated" your software through iTunes then your contacts are probably still there. I had something similar happen to me once after a software update. I thought I had lost my contacts but all I did was open the contacts app and I hit the little refresh button on the top left (semi-circle with an arrow). They then re-appeared. Hope this works for you.
07-13-2012 06:08:53 AM
Restore your phone from the backup it made in itunes prior to the iOS upgrade.