Have a look at TTTS and a few checks that SEB and I did - during one match. That congestion was down to another carrier - not BT. Without looking at your link all the way back, you cannot say where the congestion is occurring.
I have been using several BT links during the past few days and whilst latency increased they were providing 90% or better of their normal capacity.
M H C
taurus excreta cerebrum vincit