iPhone 7 unlocking itself

I recently upgraded from an iPhone 6 to an iPhone 7. Since having it I’ve had problems with the phone trying to unlock in my pocket. At least once a day, usually while walking, either: 1) the music in the headphones stops and on looking at the phone it is displaying a ‘your iPhone is disabled, try again in 3 minutes’ message, as if multiple Incorrect PINs have been entered or 2) I hear dialling noises and on removing from my pocket I find the emergency dial screen is active with several n