should be getting 3.7M down but profile keeps dropping to 1.7M

[#1]

i called plusnet and they've asked me to raise a fault which i have.
but the bt speed test is interesting:
Download speedachieved during the test was - 1460 Kbps
Your DSL Connection Rate :4544 Kbps(DOWN-STREAM), 952 Kbps(UP-STREAM)
IP Profile for your line is - 2000 Kbps
why is my IP profile set to 2000Kbps?  the plusnet tech guy set it was set to 6000 and my modem stats are 4,500 always.
any insight or help from other members would be appreciated.

[#2]

At some point over the last 3 days your router will have connected at between 2272 and 2248kpbs which is why your profile is at 2000.
If you stay connected at 4544 for 72 hours, you should see the profile increase to 4000 and the speeds on a speedtest increase to around 3500ish.

[#3]

from my router stats:
Uptime: 3 days, 2:58:32
DSL Type: G.992.3 annex A
Bandwidth (Up/Down) [kbps/kbps]: 952 / 4,544
despite this i'm still seemingly capped at 2000, latest speed test was 1.8M.  any idea what the problem is?

[#4]

max99,
you might wish to read this: http://www.kitz.co.uk/adsl/IPprofile.htm#stuck_bRAS_profile
There's also a lot of other useful info elsewhere on the page.
It may be worth raising a ticket specifically mentioning 'Stuck BRAS Profile' and post the ticket number in this forum thread, it should be picked up by the helpful staff.
Good luck.