Thank you for your feedback, Melih! Sorry to learn that you are not satisfied with our service. We have indeed thoroughly checked your video card and could not identify any problems.
Afterwards we advised you to bring your computer in. It has been here for 2 days, before we could start working on your system, you contacted us and said you wanted to come back and pick it up.
We strongly suspect that there is something else wrong with the system, which is why we also recommend that you have your entire system checked by us.