Most cooker knob shafts are shaped like a D and the recess inside of the dial/knob is a corresponding shape with a small sliver of spring steel to keep the knob on the tap shaft. I dont know what you mean by 'unashamed in' but I suspect the knob is jammed in its recess. Either way, with a pair of long nose pliers or similar, you need to get the knob out and off the shaft and you can then decide whether you can carry out some repair to stop the dial being 'overturned'
When all else fails go to:
http://www.espares.co.uk/parts?k=neff+b1441+control+knob.
You may have to hunt through a few pages to find your dial (cos there's loads) but at least you know what it looks like.
GB in Wales, February 2013
