Cannot unsubscribe from Newsletters

I will be closing my account shortly because I cannot unsubscribe from newsletters.
Firstly, the link in the newsletter email goes to a "page not found" error. I reported this 2 weeks ago.
Secondly, I logged in and unsubscribed from newsletters in the "my account" section. I still get the spam.
It's a shame you need to lose customers rather than have a quick fix for this?