can you post stats from your router please
enter phone number and post results remember delete number http://dslchecker.bt.com/adsl/adslchecker.welcome
try quiet line test dial 17070 option 2 should be quiet and best with corded phone
are you using test socket?
sorry took me a while to figure out how to upload that screenshot im a noob ,we had the engineer out a few weeks back he tested the phone line said it was within range im at a loss with this to be honest