Hi Ashflowtuff,
To turn off the TV, please press the power button on the included remote. If you hold down the power button for too long, it will cause it to reboot and turn back on.
If you continue have issues, please contact us at 1-800-SAMSUNG, 8AM - 12AM EST, 7 days a week, or Chat with Us on Samsung.com: https://www.samsung.com/us/support/contact/
~Samsung Advisor