Update
Just in case anybody else finds themselves in this situation...
Download speeds of 428kbps constant throughout the "10 day tuning phase".
No improvement on any day.
Several phonecalls to customer services. They tried suggesting they send me 3 new micro filters and a new router. I told them I had 3 already (and tried all) and was not prepared to fart about any longer. I would pull the whole contract if it was not remedied as I would consider it breach of contract.
They then escalated it to a customer something or other team and I got given a ticket number.
I phoned them last night with the full intention of arranging collection of my sky box and all it's accompanyments. I was then put through to somebody who "tweaked" my BB and told me it had been capped at 1meg (we have a 2 meg package and my line can support 3.5).
I am now averaging 2.3 meg download speed on a 2meg package (Sky basic).
Do they just 'test the water' and see if they can fob you off with crap until you complain?