Our TV reset itsself to sales pitch

Question

Our TV has suddenly reverted I guess you'd say to showing us all of the reasons you should "Buy this TV".  We can't change the channel, turn it off (without unplugging it) or anything. We don't have a remote for it and we'd bought a universal remote but it won't work on this TV. My serial # is 41099039 And my email is [e-mail]'ve unplugged the TV and let it sit for a while thinking it might reset itself but it hasn't.I get a large black box in the middle of the screen. The sound is good and the picture is under the solid black box. I have used all the buttons to remove the display screen. The picture stays on for about 10 seconds then the black screen appears.