I'd start with a very simple email to whoever runs the channel, look in Contact Us or where ever you can find this information...
Keep it short and to the point.
"This is my Copyright Protected Intellectual Property. I have not given you express consent to reproduce it. I would appreciate your taking it down immediately. "
Link the video in your message anyway possible, a URL link should work.
See if it disappears. If not, wait for a reply (72 hours seems reasonable). If they reply contesting your request this is a good thing, don't fret.
My feeling is once you send the email they will take it down. If not, it really depends on how much energy you're willing to put into having the matter resolved, so start w/ easy steps first.
Good luck, let me know how this works out for you.
Best wishes,
~Dylan