Why is that I keep getting the same junk emails even after I identify them using the this is spam buttton?
Are the messages being moved to the Junk folder or Norton AntiSpam folder? If so, that is the expected behavior. Spam filters normally do not delete or block messages - they only put them in a reserved folder. If the messages are not being put in a Junk folder, but are continuing to appear in your Inbox, then a message rule needs to be created in your email client options to MOVE any messages with [Norton AntiSpam] in the subject line to the Norton AntiSpam folder or Junk Folder. Marking messages as spam simply trains the antispam program to recognize those messages as spam and handle them accordingly - it does not prevent you from receiving them.
Norton moves suspected spam to either the Junk mail folder or the Norton AntiSpam folder. If you are not finding it, then something else may be going on - perhaps your email service is catching the messages and keeping them in an online Spam folder accessible through webmail.
In your email client or web mail web page, look for a Spam or Junk folder.