Someone using my number on various accounts

Today I received a sms stating I owe makro R14894.64 and the name is L Luzile Mbatha, this number is not owned or paid by said person, I get regular calls from debt collectors saying I should pay or I will be taken to court for non payment on an account I do not own, I regularly call these companies and tell them that the number is owned by me but I am being brushed off and getting sick of it, this needs to be resolved the right way and fast.