So just to keep this updated.
TalkTalk called back today. I was most frustrated to hear that absolutely nothing has been done inside TalkTalk to resolve. All that occurred today was that I had to repeat the basic fault finding steps AGAIN, for the 4th time. Restart the router, restart the YouView bow, reset the YouView box...
It appears that TalkTalk think that by constantly resarting \ rebooting the servcies wil magiaclly come back on.
Then after another wasted 40 minutes of my life, "let's book an engineer to visit". The soonest an engineer can come is 31st December!
Not making this stuff up, TalkTalk's customer service has hit an all time low.
I really can't face the trouble but I will not be staying with TalkTalk, if anyone from TalkTalk really cares.