White Leather Sofa, yellowing

I purchased the Visa Vera Modular Chateau dax sofa back in 2008, since I've had the sofa, the coloring has yellowed in the back and it's not from the sun. I've contacted macys several times since I've had the sofa and mind you, this is far back as 2008 and Macys wouldn't do a thing! I called manufacture, and of course, they are trying to sell me another one! If I had to do it over again, I would never ever buy this sofa, it's a waste of money. the quality of the leather is very poor!