poor quality tiles sold to me

I bought the marble white and black highlight tiles at tile 4 all, Corlett drive, when we installed the tiles, it turned out that the white was loudly different from tile to tile, the one is cream white, one is dark shaded white, one is normal white. I called the shop to come see the mess, they came and confirmed that the colours do not match. i asked for exchange of tiles, they refused and said i must wait for 2 weeks to see if the colours are not changing. if after two weeks the colours have not changed, the company will hire someone to come and replace the tiles for me within 2 weeks. 3 weeks has gone by now, the company is telling me to contact the supplier, things are out of their hands. a guy called Thomas has been assigned to help me and he says he won't help, I must wait for a guy that is in Kenya to make a conclusion on the matter and they do not know when the guy is coming back. Thomas said it was my responsibility to unpack all the tiles and check if all the tiles were matching in colour, although the label identified the tiles as white. At that moment i have no place to stay because the house is waiting for the replacement of tiles to be done before they can install the toilet and the shower. they are refusing to take responsibility now for their poor quality tiles. i advise everyone to watch out because they sold me reject tiles and they also confirmed that the supplier says there is variation on the colour but still won't help replace my tiles. the attitude on this Thomas guy is so unspeakable and very unprofessional. it is the shop/supplier's duty to check quality on the tiles before selling not the customer.