Phone App Freezes/Not Working

Since I upgraded my iPhone 6 Plus to iOS 9, and even now with my new iPhone 6S on iOS 9.1 my phone app is frozen. Basically, i cannot access my phonebook and technically I cannot make any calls. I even tried restarting my iPhone so many times but it does not work at all. I don't know what to do. I really hope that Apple will do something about this really soon. This is really annoying! APPLE, PLEASE DO SOMETHING! I HAVE A PHONE WITHOUT PHONE FUNCTIONS!!!!