Go to this Link

http://www.facebook.com/deactivate.php

And Select the Reason My Account Was hacked!
There's an Information Dialogue popups Says "You can Secure your Account here"
as you can see here in Snap Shot...
Select that Link


First Step is very important.. Do not miss it...

Please not that if you does not change your 'Name' in account settings and try to deactivate the account with option
"My account was Hacked" then you will not be given the option to change the name...
( For Those Peoples whome are facing Still The problem with it )

Credit To MinSoeYarSar