Please stop sending me SMS's

<p>Every day, I receive an SMS telling me "you have no active internet bundles etc". At the end of the message, it gives me an option to opt out. Although I have opted out some time ago, I continue to get a message most days. If I now select to "opt out", it tells me that "you have already selected to opt out" - so what do I do now to get you to stop?</p> <p> </p> <p> </p>