Upgrade 6.0 killed my iphone 4, error msg 2001 failed to restore...dead

My IPhone 4 is completely dead after downloading the 6.0 upgrade. During the restore process I recieved an error msg 1602 the first time and when I retried I recieved error msg 2001. Now I can't get any action out of it at all via USB and only get connect to ITunes when plugged into the wall. Was working perfectly untill I did the 6.0 upgrade... HELP.