I DO NOT HAVE A LANDLINE NUMBER NOR DO I LIVE IN JOHANNESBURG

I keep receiving an SMS to say My Landline number ********** 353 is suspended. I DO NOT HAVE A LANDLINE NUMBER NOR DO I LIVE IN JOHANNESBURG. I phoned last week and requested that they change the number which they are sending the sms to. they said the cannot help me as this is not my account. I called the land line, the person that answered said My cellphone number belongs to her husband. could someone please rectify this issue. it's really annoying.