Tatasky - Charged forcefully for setup box

My tv started showing video signal not connected. I lodged a complaint on **/**/** with Tatasky. Their technician came and told me that the setup box was creating problems and I will have to pay Rs. ***/ for the new one. When the tv was started again with remote the service started working but after some time the same box appeared that video signal not detected. I told him that on restarting the services started again. He said that the box was faulty. He changed the box and started the tv and went away. After a fixed time again the services stopped and the same box appeared saying that video signal not detected. The technician took along the old setup box. He gave me his mobile number and I called him that the same problem has reappeared. He said that he will come and see. But he didn't come. So on **/**/**, I lodged another complaint with Tatasky and a new technician came. He said that there was nothing wrong only somehow the timer was set up for a fixed time and after that time the services stopped and on restarting the services resumed for the same fixed time. The technician who came on **/**/** also came at that time. He was told by the other technician that it was the timer that was stopping and the setup box was not faulty. I told him to bring my box back. Why should I pay forcefully for a new setup box? Then I got a call from Tatasky and was told that there was a talk with the technician and I was not going to be charged for the box. Yesterday on **/**/** all of a sudden they charged for the box as you can see attachment. I am being charged for the inexperience of their technician. My services also have been stopped. You can see from the attachment. It was the mistake of their technician and still, I am being forced to pay for the box.