Running the update again, or resetting the phone to factory settings (backup your data in either case), will help determine if the issues stems from SW or HW.
If there is no change after you do this, HW is the most likely cause. At that point, you'll have to call us to discuss warranty status and the process to have your issue investigated.
http://www.sonymobile.com/global-en/support/contact-us/contact-info/
