P C Net ComPuter DoCtor

Brought my computer in for repair and had to bring it back several times. I paid for repair but is not fixed. Want a refund.
May 29th I brought my computer in for reformatting and reloading Windows 7. It would not boot up. On June 3rd the owner told me it was fixed and I could pick it up. He said the charge was $119. When I picked it up, he changed it to $219. I know $119 is on the high side of normal for this service but $219 is overcharge. He would not back off so I had to pay $219. When I brought the computer home, it was not fixed. The system would freeze up and would not boot so I took it back. After keeping it several days, I was told I needed a new video card. He removed the old video card. I had to get another cable before I could use my monitor and that took about a week as I was out of town. When I got it reconnected, I found it was still freezing up and I was unable to install my programs. I took it back to him. He kept it for 2 weeks then told me I needed a new hard drive which I purchased for an additional $100. The computer is still not functioning correctly. It will not download any windows updates which makes the computer vulnerable to viruses. It will not update my virus software or any windows programs. I do not want to take it back to him as he obviously lacks the skills to fix the problem. I just want my money back so I can take it somewhere else.