Harassment day and night due to call divert snarfu

Please get Xoliswa Cebisa to call me (she has my details). I can't get through via your user-unfriendly MTN contact numbers. MY CALLS KEEP GETTING DROPPED!! She assisted me this morning regarding my 80 year old mum's number that has apparently been erroneously used to divert calls to. Mum's cellphone rings every two minutes and disconnects as soon as the call is answered. Left unanswered a 'please call me' message shows. (288 messages and 58 answered calls in December alone). Xoliswa attempted to sort this, however the harassment from caller *** still continues and also from ***. How is it possible to divert calls to a number without the consent of the owner of that number?!!! I NEED YOU TO BLOCK THESE NUISANCE NUMBERS PERMANENTLY AS YOU MTN, IN YOUR INFINITE WISDOM, HAVE CREATED A SITUATION WHERE THE DIVERTOR IS PROTECTED AND IN CONTROL BUT NOT THE UNFORTUNATE DIVERTEE (both of whom are paying customers). Mum's forced to keep her phone turned off day and night which defeats the object of her having a cellphone for emergencies. Is this a **** that MTN is protecting or will this be resolved asap? Kindly post your replies - in point form - to my questions.