Once you have provided the information needed below, the community members can then help you.
A summary of the checks are:
1) Are you connected by master or test socket?. 2) Can you please run a BT speed test (including IP Profile)http://speedtester.bt.com (not beta version)[Best done with a wired, ethernet, connection] 3) is there any noise on your line. dial 17070 option2 from landline. should be silent but slight hum normal on cordless phone. - 4) please post adsl line statistics