Review To start. my mother is 82 years old a pensioner and has a 100% rebate. and being harrased by Credit

This company keeps calling and now sending SMS's to my moms phone say that she owes R********.00 something to the city of Johannesburg.
So to say she is covered by 100% Government re-bait. so how could she owe this amount. she will not acknowledge this amount because she dose not owe this amount. she is a pensioner. 82 years old with bad eyesight and bad hearing.this company cant even provide the document showing she owes this amount and why. and top of that she signature inst even on it. so where is that. she has never received a statement on this amount ever. so how can it magically appear out of no where. i am going to email 3rd degree on this and any media i can.