FTTC Install, 2nd Socket and Distance

[#1]

Hi All,
Had my FTTC installed yesterday by BT. They came and replaced my master socket with the VDSL plate and tested the line 20.5mb was the max speed and this was reporting being 2.8km from the Green box, which was impressive, as by the road i am only 1.3km away.
I then had run some Cat5 cable to a 2nd point in the house which had a RJ11 faceplate at the end, the BT engineer said that it wasn't the reccommended way to install this but tested it anyway and i only lost 0.2mb from the line. We plugged the Openreach modem into the RJ11 socket and it connected fine. Speedtest.net was showing:

I came to the connection this morning to find the download speed was slow, so slow that it was worse than my old ADSL2+ connection. I restarted the BT Openreach modem and no improvement but doing tests found my upload speed was still 2mb up but 0.20 down.
Anyone else had any of these issues soon after installation?
Chris

[#2]

My speeds have been a bit up and down, but nothing like you're reporting.  I've done speed tests using wireless, homeplugs, and direct network cable, as well as via my VPN connection to work; and the differences were significant, but as i said, nothing close to that slow.
John

[#3]

Hi Chris,
As per my reply to your ticket, I've fixed the problem, it's the same thing that's affected a couple of other customers where the ADSL speed changed just before the install but the change didn't filter through until after you were installed. We'll work on a way of fixing that when we go live but will keep an eye on them manually for now.