Very low profile despite good stats

[#1]

The profile seems set to the lowest level even though it used to give good throughput and the noise margin is huge:
1. Router stats show:
[tt]--- DSL Information ---
DSL Driver Version:  AnnexA version - A2pB023k.d21d
DSL VPI/VCI:        0/38
DSL Status:          Showtime
DSL Mode:            ADSL2+
DSL Channel:       
DSL Upstream Rate:  1152 Kbps
DSL Downstream Rate: 283 Kbps
                      Down        up   
DSL Noise Margin:    34.8 dB      6.4 dB
DSL Attenuation:    28.5 dB      13.7 dB
DSL Transmit Power:  0.0 dBm    12.4 dBm[/tt]
2. speedtest shows 181 kbps downstream (!) and 916 kbps upstream. The detail from the BT one gives:
"Best Effort Test:  - provides background information.
...
download speed achieved during the test was - 0.17 Mbps
For your connection, the acceptable range of speeds is 0.1 Mbps-0.25 Mbps.
IP Profile for your line is - 0.25 Mbps
Upstream Test:  - provides background information.
...
Upload speed achieved during the test was - 0.98Mbps
Additional Information:
Upstream Rate IP profile on your line is - 0.83 Mbps
We were unable to identify any performance problem with your service at this time."
3. From plusnet:  "Estimated line speed: There's no speed estimate currently held on your account. Current line speed:0.2 Mb "
My relatives used to only switch the modem on when using it, but I have left it on (apart from occasional reboot) during the last 48 hours. Is this enough to let the profile increase after a few days or is there something else we can do to encourage this to happen?
I have raised a question in the plusnet Help Assistant (96680746), but I expect they have few (if any?) staff and many queries over the holiday.
Thanks
damar (plusnet account name)

[#2]

If it matters, I think it is a 21CN line.

[#3]

It is 21CN based on the upstream rate, however the downstream is severely banded, possibly a side-effect of the relatives powering off the modem when not in use. It could well be that the profile has stuck, and this needs a SNR reset. May be the best thing to do would be to raise a fault here. If you can, point to this thread and suggest a SNR reset.

[#4]

Deleted - not relevant

[#5]

Does anyone know what hours/days customer services are open over the holiday?
I asked a question on the 23rd and have updated it once or twice since and it still says:

Quote

You currently have 1 open question Date raised  Question ID  Status 23 Dec 2014 96680746    Awaiting support team answer

[#6]

and every time you update it - it goes to the back of the queue

[#7]

I see that one of my colleagues removed the banding on your line and it's now syncing at over 16000 again. Hopefully you're not seeing any issues now.