HELP STOP WOOLWORTHS FROM SENDING OUT SPAM

I have on countless times phoned and emailed Woolworths to take me off their SPAM list - to no avail. When you speak to someone directly they assure you they will but to no effect. I have asked them and told them that by law when someone asks to be removed they MUST remove the email but no reaction from them. When you attempt to UNSUBSCRIBE it makes no difference you will still receive an unbelievable amount of irritating SPAM from them. Please can someone tell me how to stop Woolworths and permanently unsubscribe them or who do I approach to lay a charge against them