Very Low Maximum Download Speed

[#1]

So in our house we were having connection problems due to a poorly router constantly dropping connection. Now we have a new router installed but our connection is very VERY slow.
I have run through all the diagnostics and self-help guides and we are running the router through the test socket of the master socket on the wall but still when I run the BT Wholesale speed test it is reporting that our maximum download speed available is only 0.25mb.
Before the router problems we were definitely getting much higher speeds than that, so does this mean that we are being throttled by the exchange because our line was seemingly unstable or could there be another cause for this low maximum?
It has been 48 hours since the new router was installed and the speed is still slow, I know they say it takes three days for speeds to increase but is that a sudden switch after 72 hours or should we be seeing a gradual increase by now?
Any information would be helpful, thanks 

[#2]

What are the router stats - noise margin, speeds and attenuation

[#3]

Copied straight from the router page

ADSL

Type Interleave Path

Status SHOWTIME

Downstream Upstream

Data rate(Kbps)       287               446

Noise Margin         25               27

Output power(dBm) 12               14

Attenuation(dB)         17               10

It's a Belkin N300 (ADSL 2+), which should be able to give us speeds up to 300mb/s. I am 90% certain it isn't a router problem though because we are still getting a crawling speed when using the plusnet provided Thomson Gateway router.

[#4]

Because of the instability problems the line has been banded http://www.plus.net/support/broadband/speed_guide/broadband_terminology.shtml at the lowest possible sync speed
I am not quite sure the best way of getting this sorted but I would suggest leaving it in the test socket and when the Digital Care Team come back in on Monday they can check the line stability and then get the banding lifted

[#5]

ok, thanks.
Are the digital care team likely to resolve our issue automatically or do we need to report a fault or contact someone?

[#6]

Your speed should have picked up again now, one of our faults team had responded to your open ticket and reset the SNR on your line.