with your attenuation, which is as high as router displays even though true figure may be higher, a coonnection speed of 1.9/2mb is about right. however with your noise margin at 10.8 you still have some scope for a faster connection if you can get noise margin down to 6db
are you connected to master or preferably the test socket? do you have extension sockets?
can you run btspeedtester and when first test completes then run diagnostic test and post results
try quiet line test dial 17070 option 2 should hear nothing and best with corded phone if cordless then dull hum normal. any hiss/crackle need to be reported as a phone fault which when fixed will help your broadband
as you say the real problem is the length of your line from the exchange
I think hard luck as the work needed must be seen as a profitable outlay as it not like the old BT as this company now has shareholders who want a return on their investment. no different to virgin - you don't see them laying new cable to sign up new clients