This thread has gone way off topic.
In this case no harm in that as my first reply was pretty comprehensive and the OP has gone walk-abouts.
I'm in the same situation as the OP. I have the same Mobile/broadband deal at the same price at the OP. Orange broadband as to be the worst in the UK. I can't believe customer service could get worse. I am promised an up to 8Mb but I usually get 1Mb or less. The only time it approaches a decent rate is early morning when I can get 5.5Mb. I can't help but think they are deliberately throttling those of us on the cheap broadband.
Are you just agreeing with the OP and having a (fully-justified) moan, or do you want some suggestions? Depending on your exchange they may be different, and line stats could be useful.