Refer to this thread to get your phone working again:
Now that you've unlocked your bootloader, you can't get updates OTA. So don't do that and brick your phone again! Also, depending on ho...
Follow this link for the fix. Then never touch OTA again! :)
Wooo! Just got it unlocked! Thanks Alejandrissimo!
Process took 5 or 10 mins and all I had to do was sit there and watch :D
Now have the magical blue-LED of fastboot on my Roger's Play :D
Edited to add: TrackID works. After final...
Go settings -> Sony Ericsson. It's in there