Need some help with my new Note 4 and voice mail

[BJM9282]

I'm having an issue where the screen doesn't turn off while listening to voice mails, so my face is inadvertently pushing buttons and stopping the voice mails in the middle of listening to them. It's really annoying. Is there a setting somewhere to activate/deactivate this feature? It works fine when making a call, just not when listening to visual voice mails. Any help would be appreciated!