Also no need to make multiple threads regarding this. Youve already been answered before this thread and have made two prior threads regarding the same thing.
http://community.us.playstation.com/t5/PlayStation-Network-Support/Sign-In-Changed-But-I-DID-NOT-change-it/m-p/45674275
http://community.us.playstation.com/t5/PlayStation-Network-Support/help/m-p/45674276
http://community.us.playstation.com/t5/PlayStation-Network-Support/Sign-In-Changed-But-I-DID-NOT-change-it/m-p/45674275
http://community.us.playstation.com/t5/PlayStation-Network-Support/help/m-p/45674276