Colour and material change - Consumer Complaint for Bradlows - Head Office

I bought sitting room couches black leather but two of the six pieces change colour from the original black to greyish and the material also changed. I reported the case with my salesperson many times.I ended up demanding the next person senior that her since she was not helping.She gave me the manager who also did not help me it's been four years now I am a very unhappy customer.This also makes a bad name for your company do you know that one unhappy customer will pass it to ten people and the ten will pass it to their ten people.