"Believe it or not, witchcraft is a serious problem in Pakistan..."
No, the fact that anyone even believes witchcraft exists is a serious problem in Pakistan -- and Saudi Arabia, and South Africa, and anywhere else they are still believed, on an official level, to exist.
"...I believe in them completely and I think that they should be punished like this. These types of cruel punishments have the biggest deterrence than any other punishment."
First, deterrence by such means DOES NOT WORK. It has never worked, or crime would have disappeared during the time of the Romans, when the most inventively cruel punishments were devised and widely implemented. It flourished instead.
Second, you are talking about "deterring" people from committing a "crime" that DOES NOT EXIST. Sure, it's on the books, but in the present case, it isn't even defined, much less shown to exist. Punishing people for such a crime is ridiculous, because they cannot possibly have committed it; deterring others from committing it is equally ridiculous, because it would be impossible for them ever to commit it.
How, in the 21st century, can so many supposedly grown-up people in this world still believe in freakin' MAGIC?!?
~David D.G.