I've started replying to the emails when I unsubscribe. Just gibberish or the word "unsubscribe" or something. That way if they email me again I can complain to them with the exact date that I unsubscribed. I feel like I'm turning into a grouchy old man, but I've caught more than a few companies this way over the years and it brings me joy when I do.
In eurolandia one usually sicks GDPR on their behinds. Low level scum may ignore it at their peril and companies with high exposure will comply really fast.
