Ex-student keeps receiving unwanted emails.

For over a year now I have been receiving email notifications about calendar updates and items posted. I have spoken and requested on several occasions that I no longer receive these emails as I am no longer a student there. I have tried unsubscribing, but when I place my email address in, the very same email address the site emails me on, it says that it does not recognise my email address. I have informed AFDA of this problem and all the details pertaining to it, but still nothing has been done about it.