Keep your mouth shut and get lost.... My dear friend, visa is not in hand of any tour operator. You should had good supporting documents. And if the tour was full that was the reason SOTC must have shifted you to an another tour. My experience with SOTC has always been perfect. Suggest you not to defame any company because of your shortcomings.
All the best for your next trip and still suggest you to travel with SOTC itself as they really have very good and comfortable tours. I myself has tried so many operators but found that they are the best in the industry.
Happy Independence day.