Edgars is harrassing me for an account that has been fully paid up

I had an account with Edgars that I closed paid up and closed back in 2012. I an sincerely not interested in that account and have no plans to ever use it ever again. Edgars people have been calling me asking if I am aware of the account and I have been constantly telling them that their calls are unappreciated and that I would like for them to stop calling me as I have no interest in them or the zero balance account. I now feel harassed by them and fed up of explaining the same thing. I do not see how difficult removing a number can possibly be.