Cheers for this X.
I'm definitely going to phone them tomorrow, but I have my doubts as to what they can do.
I have to say though, and I say this with zero technical know how at all - but I can't help thinking there must be something wrong with the line. I've been on Sppedtest.net every day since we got the Sky BB installed, and just yesterday I noticed that I could check previous tests; it transpires that back in August last year there were occasions when I was receiving over 5Mbps. It tumbled down to under 1 Mbps in September, and hasn't been above 1 until the first day with Sky last week. I do vividly remember it being far faster than what I'm receiving now, and I also remember phoning Orange on various occasions and getting short shrift.
I've read a few things online about line noise, attenuation (sp) etc, but I've no idea how to check these and whether or not they'd be a factor.