September 13, 2012, 5:44 PM — Here's how you can disable FaceTime calls in iOS 6.
1. Open the Settings app.
2. Tap on FaceTime.
3. Toggle the FaceTime switch to the Off position.
4. You will no longer be able to send or receive FaceTime calls on your iPhone, iPad or iPod Touch devices.
5. If you want to reenable FaceTime, just toggle the switch back to the On position.