Wrong coloured windows

Hello, I had with down fitted by everest, they did not fit from the beginning and the colour was really dark,almost black. I had ordered charcoal, grey but been shown no samples. I had trouble with the as one of the windows fitted, They are now replacing the windows and I have found out they have fited the wrong colour. All this has taken over 3 months already. The house is freezing as the windows dont fit they are supposedly making replacements . Can I demand a full refund?