I've had exactly the same problem for 3 weeks now, I thought I was alone!
It's shocking that a huge company like BT, spending millions on TV and radio advertising, does not have any customer service training or English people in the UK to talk to. Why are they still trying to sell their products when they cannot maintain the existing customers' goodwill. It's disgusting. Unfortunately I'm tied into a 12 month contract but will be running away as fast as I can when it's over.
I'd really appreciate it if SOMEONE - ANYONE - from BT would have the good grace to contact me to apologise or explain what on earth is going on with my broadband service. ANYONE OUT THERE? or are we just being ignored?
and use this speed tester then carry out the further diagnostics and post back a screen shot of all the results including your IP profile for up and down. This test must be done with a wired connection.