Just leave it connected as instructed, and it will sort itself out.
Can you hear any noise on your phone when you dial 1470 17070 and select option 2?
After a month of it being connected it didn't sort itself out, how long am i supposed to wait? Perhaps give it a year maybe?....
A faint fuzz, but that could be my old rubbish phone.
you are not being asked to leave it connected for weeks or months just for the next few days but to ensure your router remains connected to the internet you need to check your router stats for connection time and ensure this as you would expect. your router can drop connection anytime and only by checking the adsl stats will you know.
if you get the 5 days conenction time and connection speed still the same then you will get help from the forum mods who are the only BT employees on the forum - rest are customers like you
Some pointers for you to consider:
Firstly, you've not been lied to .... BT speed testers base an assumption on line length, and the pre-requisite that they are healthy. (before you buy)
Secondly, just because the lines are new, doesn't mean that the main master socket line is condusive to good broadband.
Thirdly, broadband is line derivative which means basically it has to pass some noise tests to perform efficiently.
And lastly, if you are to get a good result, you need (with respect) to listen to what forum members tell you to do.
It's all been seen .... and sorted before.
The thing to do is answer the questions as accurately as you can, and take instruction, and read any links to help that
Keith or John (or others) give you.
Fixing broadband can be time consuming, and more so, if not done to procedure. (temper or attitude doesn't fix it)
So what may seem as a given (because you pay for it) is not always the case, and help is required.
But you'll only get that help, to help your self, if the advising party sees mileage in it. (with respect again).
Follow instruction, it will be worth it. 😉