Just run another test after a lengthy conversation with my ISP.

I have been informed that the maximum my line can handle it 512kbps. On this basis, the 370kbps I'm actually getting isn't too bad, although I don't see why I should be charged the same price for "upto" 8 MEG as someone else who can actually get 8 MEG. Damn disgrace.
They've told me to run some additional tests with
http://www.speedtester.bt.com 3 times per day for the next week, and call them back. Not sure if I have to record the results or if they're logged somewhere the ISP can access.
The results were :
Download Speed Achieved : 302kbps
DSL Connection Rate : 928kbps (DOWN STREAM) & 448kbps (UP STREAM)
IP Profile for line is 350kbps.
If someone could explain what the hell all this means, I'd be very grateful
MANY THANKS.