I had a similar problem with SunLife marketing emails. I would unsubscribe from everything there was an option for, then a month later I would get another marketing email setting personal finance advisors. I spoke to support to be told how to unsubscribe, then that it "was an account information email not a marketing email so I cauld not unsubscribe".
Eventually after escalating I was put on a do not email list and haven't received emails since; though they do still send crap to my work email.
I tend to have a policy: I will click on your unsubscribe button once, after that it's straight to 'report spam'. If that sinks your domain ratings, that's on you.
Eventually after escalating I was put on a do not email list and haven't received emails since; though they do still send crap to my work email.