Towards the end of the movie, the religious leader asks PK, if what you say is true, that all calls are going out to the wrong number, then what is the right number? Now this is the tricky part of religion. The moment one ascertains and states definitely that this (or that) is the right number, one goes wrong!
Truly speaking, Religion is not about right or wrong - that´s the work of ethics. Religion is all about being beneficial or harmful. It is an additional help, a means for those in search of God. Of course, some use it as the most easiest and prompt answer, with the conviction that riding on the wave of religion will automatically lead one to God, without any personal effort or strain.