bt slow speed

Have had problems this weekend with my bt speed. Pay for up to 8meg and sometimes get about 3 or 4 meg. Have intermittent trouble. Last night had dropouts and very slow speed. At speedtester.bt.com 3424 up/ 448 down/ 427 actual throughput. Just ran test again and had 6208 up/ 448 down and actual throughput 0k. Have phoned bt 3 times this weekend to report noisy line and bad speed. Always same rubbish. no actual help. Say it will cost ME £125 if engineer finds no fault. There must be a fault , had speed of up to 4 meg just a couple of days ago. This happens every month or so for a couple of days and BT still says there is no fault. want tio change ISPbut would not help as I'm sure there is a line fault. Still have to pay 323 a month for this terrible service. What can I do??

Noise line, as in you can here the noise? First check, unplug ADSL modem if it goes away, then it may be faulty filters or wiring.

I presume you mean 6208 down, as there is no ADSL with an upstream of 6208. If you modem is disconnecting and reconnecting a lot first step is to actually look at the connection speeds rather than the speedtester websites, and then see if things improve when using the test socket.