This is all guess work, based on not that much information right now.
On only a few occasions have I had to send a job back as 'Long line issue', giving extensive feedback on where in the network the circuit can attain synch (ie a Carrier Pole or a Cable Joint), and beyond that point it is literally to far to support DSL.
As most posters on
Kitz will be aware, if the circuit loses synch when the phone is used, there's a damn good chance there's a high-resistance fault lurking somewhere ??
What speeds were you getting before, do you know ??
How long have you had an ADSL connection ??
We really need more info than what is currently available to us I'm afraid, to be able to give opinions.