Have you checked the line yourself with a phone, as the problem may be intermittent noise?
Yes, but if there is noise you would need to repeat it at the test socket to eliminate your internal wiring as the cause.
I think this is going to have to be looked at by one of the moderators, would you agree @licquorice
Yes, probably the only way to get an engineer visit.
Thats much appreciated!
I have asked a moderator to provide assistance, they will post an invite on this thread.
They are the only BT employees on this forum, and are based in the UK.