Instructions
Turn on your PS3 console and scroll to the "Users" tab located in the far left corner of the XMB menu.
Scroll down and highlight the user name that is associated with the PSN account. Press the "Triangle" button to show the options and select "Delete" from the submenu. The user account associated with the PSN will be deleted.
Call a Sony Computer Entertainment America customer service representative at 877-971-7669 to request a ban on your PlayStation Network account. Give the representative your full name, account email address and home address as verification. After she is finished, your account will be banned and deleted from the PSN server.