You realise that 0.6 is over ten times faster than dialup ever was, right?
Anyhow, your line attenuation is the problem - at 63.5dB you just have a really long line from the exchange. Unless it's faulty, there's nothing you, BT, or O2 can do about it. By those numbers alone I'd guess you were 4.5-5km from the exchange.
Have a check on
http://www.samknows.com/broadband/broadband_checker and punt in your postcode and phone number. It should estimate your line speed and your distance from the exchange. If either of those are way off, let us know what they say but if they're about the same then you're SOL. You might be better off switching to a mobile broadband solution depending on where you are.