YOu cannot blame the companies or employers. They might have found better than you. It all depends on your luck and time. If everything works fine, you will get the job. It happened to me too. I had been selected in Saudi Arabia and they asked my Passport copy and educational certificates. After two days, they sent me email that they have postponed the hiring. It all depends on our luck brother. Keep trying and keep on trying. Don't loose the hope. All the best