Vodacom - a very slow learner!

As a technologically advanced company active in the telecoms industry, Vodacom should have found a way to prevent ongoing marketing calls to customers who do not wish to receive them! Three months later and some 20 or 25 calls later, I have had to start blocking telephone numbers to avoid their marketing calls. Even a 3 year old child does not require so much repetition to get the point! Even threats of reporting to the regulator seem to have no impact (I suspect staff have not been sufficiently educated about the opt out effect).