Promotional text messages

I receive promotional messages from Woolworths on a daily basis. I have repeatedly tried to have these discontinued - without success. I went to my local Woolworths store at Loch Logan Waterfront in Bloemfontein two days ago (19 December) and Chantelle at Customer Services called head office. The person Chantelle spoke to assured her that, while Chantelle was holding on, she had called IT services and that my number had been removed from the databasis. The very next day, and today, the text messages continued as before. I called Chantelle at Customer Services yesterday and she assured me that her store manager would mail head office in this regard. So, either the store manager has not done so, or even individual stores have no success in this regard. WHAT is one to do?!