Refusing to replace a unit, pathetic excuse

They have messed up my computer to a point of no return. I took my PC in to be fixed. As brief as I can explain, my PC's screen was replaced even though that wasn't the issue, it was software related and needed to be wiped (which was stated on the service sheet and not done). They then Manually wiped the computer after I sent it in again. The screen was put in wrong with a film left on the LCD. I took it back and it was removed. My computer then got progressively worse in 1 day. Due to the manual wipe, they removed vital programs on the computer like, Steam (which now doesn't work even when I try download it myself), Asus Gaming Center and the most shocking of all, my graphics card control panel and GForce experience. I then demanded a refund from Incredible Connection (which meant they had to work through Ensure again), Ensure then refused to replace the computer as it had gone through SOFTWARE REPAIRS, what? How could you even say that? That is absolutely disgusting, I was so shocked. So now I am at the point of filing a law suit if they don't help me soon. They are breaching the Consumer Protection Act, I am entitled to a new device.