My friend decided to grab my phone and change my message tone so something pretty offensive. While it's pretty funny, I have no idea how to change it back. I went to check my notification tone and my ringtone in sound settings, and it says they are the ones I had selected, not the one I'm hearing. It's also not contact specific ringtones, as I hear it when anyone sends me a message.

Is there another way he could have changed it?
I'm not using go launcher or anything, just the stock messenger.