Hi, entre your landline number at the following link to see what speeds your line is estimated to get, if your number dont work click the address check bit at bottom and entry your address...
https://www.btwholesale.com/includes/adsl/adsl.htm?s...
Let us know what speeds it gives as estimate, if they are above your current speed then you could complain, they will send engineer and then you could point out rubbish connection in loft.
Best Regards,
Matt.
"I don't take too kindly to coaxial pushed rubbish... or to them damned Intel Puma wastes of plastic."