ntl probably already told you to unplug the box, wait ten seconds and plug it in again. I had a problem with mine yesterday and had to do that. After a few minutes of alternating red, green and orange lights on the box it worked fine again.
I find this happens occasionally, probably less than it used to. It is annoying if it happens when I've set something to record though.
Anyhow, if you haven't unplugged then give it a whirl.
BTW, 8+ days for an appointment is crazy. Make sure you get a credit for the outage period. I did that before.