Hello and welcome to Apple Support Communities, sohaib195!
We understand you're being charged for SMS sent by the iMessage and FaceTime activation service. We'd be happy to provide information about this.
Keep in mind, not all carriers support iMessage and FaceTime. You may have seen a notification when you first setup your iPhone indicating that there may be a charge for activating these features.
I see Jazz is a carrier in Pakistan and unfortunately, it's not one of the supported carriers listed here:
Wireless carrier support and features for iPhone in the Middle East and India
I hope this clears things up.
Have a great day!