Edcon keeps spamming our mailing list

We have been trying to get our mailing list unsubscribed from Edcon and redsquare, but they keep spamming us. They require ID numbers and account numbers in order to unsubscribe, so it is impossible to get rid of the junk they keep sending us. Calls end up going in circles and emails remain unanswered. <br> <br> Please follow global guidelines for unsubscription policies and remove the unneeded information your unsubscription requires. Spam is NOT cool