I understand if your pissed, but instead of calling it a scam work with people to solve the problem. There are still things you can try and it would help if you post your system specs.
Have you disable steam Overlay?
Tried enabling steam offline mode?
Have you cleaned your system of malware?
are you overclocking your videocard/system?
Is your security software "sandboxing" construct 2 or your video driver??