I have the same issue with my 128 GB iPhone 7 plus .. 5 days old phone .. bought on 7th October..
The applications where i have noticed the HANG / Freezing issue:
Phone App
Text Messaging
Typing Notes
My case has been escalated to the Engineering team .. Crash logs have been uploaded to them..
Still waiting for a response / fix from their side..
Sad to know that reputed brand like APPLE has these kind of issues with their new product and customers have to suffer..
The amount of time being spent in troubleshooting to get resolution / fix or a replacement .. IS IT WORTH ?
Support or Replacement may be free but IS IT WORTH after spending so much time ??
I wish APPLE has some customer service department which compensates for this pain caused to Customers !!
NOT SURE if APPLE even bothers about what time is being spent into this by customers ..
I feel embarrassed to even discuss this with my friends who are on ANDROID..
Wish they provide me with resolution fast ..
Sukhminder Gill