Hi, fahad122,
Thanks for visiting the Apple Support Communities. I understand you have concerns over the battery of your iPhone, and have been trying to get in touch with Apple Support, but have been unable to. I'm happy to help with both!
There are a lot of factors that go into your battery life and performance. If you are worried there may be a problem with your battery or it doesn't seem to be performing as expected, you can check out the information outlined in the Apple Support article iPhone Battery and Performance - Apple Support to get more information on the battery, its capacity, and performance.
You can also use About the battery usage on your iPhone, iPad, and iPod touch - Apple Support and Charge and monitor the iPhone battery - Apple Support for more help managing your battery life and performance.
If you still need to get in touch with Apple Support after that, you can use the phone number listed for Pakistan in the Apple Support article Contact Apple for support and service - Apple Support, or choose an alternative available contact method here: Contact Apple Support.
Have a good weekend!