Is this a legitimate business you have dealt with before? Or just garden variety spam? If the former, do they have an unsubscribe link in their emails? When you use one it may take several days or more for the change to take place. But if they are consistent you could try setting up a filter to discard their messages. To do that, on the Inbox page click on the gear icon in the upper right corner of the screen, then on Settings. Under Mail in the left pane click on "Filter rules". Set up your filter. You may have to sign out of the account and back in again to get it to "take".