Finally changed that switch gear. Replaced it with a new extremely expensive OE assembly, in fact I pretty much did it twice as I fitted the lower cowling incorrectly the first time round, had it rubbing against the steering wheel, so had to take the airbag and wheel off again.

Struggled with detaching the thing directly behind the steering wheel, which is attached to the switch gear assembly, 4 easy tabs and one silly clip on the left which took some time to release (by squeezing the body of that thing) I got it into my head I should push down the recessed tab, which didn't work.

Full beam works properly now which is a huge relief.  Next some work on the rear brakes to try and improve the hand brake then the dreaded MOT early next week. The torx M10 nut seems a bit soft so I can see why they recommend a new one

Thanks all for the correct diagnosis regarding that switch assembly being the problem. 

I found this,though the assembly is different,remarkably an even newer model, my one  looks like it too can be taken apart, so I'll have a go and see if I can fix it , like this guy did

Skoda Fabia Windscreen Wipers Stuck On