Bad service, Refusing to correct thier mistake

I have a bad expriance with Greenstone branch. The job was to cover the space next to dishwasher with a cupboard instead they installed a small cupboard leaving quiet a significant gap also provided with a wrong shade of white to the door. I contacted the consultant by the name Tshego Ntlateng to correct it and the responce I get is we cannot cover the gap also they dont want to change the size of cupboard and the door to match the other cupboards. They leaving me with installation that I do not agree. All I need is the the cupboad size be incrased to close the gap and match the color.