Have you also noticed how companies ignore "unsubscription" requests for unwanted emails? How many times have I unsubscribed from mailing lists then month sometimes even years later new emails are coming with the option to unsubscribe, again.
This is one reason why I give each company a unique email address. Then, if they turn out to not properly understand the meaning of "unsubscribe" or "stop mailing me" I can just delete their unique email address and the problem is solved from my viewpoint.