I finally figured out the problem. But no answer provided here so far could have helped. It turns out that when I received the throttle, A was glued to B. I thought that this was its natural position. In fact at one point, it broke off when the device fell. In my dumbness, I added even more glue to stick it back. Try as I could, watch the video many times, asked on the forum, my throttle simply refused to work. In desperation, I wrote to Tom Dowel. Now don't laugh at me.
In the meantime, I decided to disassemble the device. Then I noticed that B should actually stand alone from A. When I turned C, it responded the way it should. I assembled the device, put the screw back and fine turned the locking system. Viola, there it was working. Tom needs to add to his notes that there are three separate parts to the device.
It is the simplest device ever made; yet, it fooled me for four days. I did not understand why everyone was telling me that it is the simplest device to install, yet I could not get it to work.
Thanks everyone for your input.