I reported the fault to my ISP, I had a reply back saying they have tested the connection and its running at nearly 15000kbps, so they implied it must be my end at fault.
I've just replied back saying, I've tried two different routers, swapped the adsl filter over and tried 3 different ADSL online speed test sites.....
Back to them

Maybe its the bit of copper that swings in the breeze going to the telegraph pole.
I remember about 15 years ago.....before the days of adsl....i wanted two 56k dialup connections to my house....so paid BT somewhere about £115 to install a new line. BT blokey turned up and installed a 'gizmo' so the two lines would share the same copper wire. I went nuts at BT when i discovered if you tried to bring up 2 data connections at the same time, you got a very poor connection speed. Apparently it was ok for a voice call and data call at the same time but not two data calls.....BT were back a few days laters running another bit of copper to the telegraph pole
