Fault fixed - thanks Plusnet (and Openreach...)
My FTTC connection went haywire on Xmas day - dropping about 15-20 times, and noise on the line. I rang the help desk on Boxing day around 4pm. Phone was answered straight away, my line was tested, and an external fault identified. I was told target fix day was Friday 29th December.
OR man called me on the Wednesday, identified a section of cable with water ingress, and said they would fix it on Friday, which they duly did.
Now just waiting for the target margin to go back to 3dB to get that final few Mbits of downstream speed back.
Just wanted to thank all concerned for a job well done.