Can't get ADSL2

[#1]

Hi,
I few weeks ago my router started dying, randomly losing it's wifi abilities requiring reboot, and all these reboots appear to have caused the exchange to reduce my line to only allowing sync in ADSL 1 GDMT Mode.
I've now replaced my router and at the same time taken the opportunity to replace my master socket faceplate with a BT Openreach VDSL Mk2 filtered one to remove the need for microfilters, I've then added new cabling using Cat5 twisted pair from the master socket to my router next to my computer upstairs.
On connecting  my new router (TP-Link TD-W8960N) I find the new router is still only syncing in GDMT Mode with same sync speed as my old router,  3936 down and 832 up. As this router uses a broadcom chipset I've telnetted in and tried tweaking the SNR and I'm now running reliably (no dropping sync) at 6272 down and 736 up.
My router SNR status before tweaking is
                Down            Up
SNR (dB):        15.2            11.0
Attn(dB):        51.0            31.5
Pwr(dBm):        19.1            12.7
After tweaking I'm getting
                Down            Up
SNR (dB):        4.3            11.0
Attn(dB):        51.5            31.5
Pwr(dBm):        19.8            12.6
Is it  possible for someone at plusnet to reset my exchange to default to re-enable ADSL2 and give default SNR now my line seems to be a lot more stable?

[#2]

Looking at those figures and your description I suspect there's an issue with your line.  Can you hear noise?  Dial 17070 option 2 - if you can hear noise report a voice line fault to your phone provider.  This should be done prior to trying to fix a broadband issue.
If the line is quiet, raise a fault report here - http://faults.plus.net

[#3]

Out of interest, what's so bad about those stats? 6272 seems a pretty good speed for the attenuation. The target SNR is presumably very high due to the dying router, so a simple SNR reset should fix that. Perhaps the upstream speed is slightly low, but that could be because the upstream margin is high and doesn't seem to have been affected by the manual margin adjusting.

[#4]

I would like to add that I found how to raise a  support ticket after posting this,  not sure if Plusnet did anything to my line yet or whether it's the exchange automatically adjusting to my improved connection but I'm currently still connecting in ADSL 1 mode but my default sync speed without doing any tweaking on the router is now 5600k  Down  and  800k up with these SNR stats  :-
                Down            Up
SNR (dB):        7.1            10.0
Attn(dB):        51.5            31.5
Pwr(dBm):        19.9            12.7
I've also been informed that my line should be switched to ADSL 2+ tomorrow so will be interesting to see what (if any) improvements this makes to my connection as their mail did mention my predicted speeds are the same for both ADSL 1 and 2+ (but then my predicted speed  is still showing as 3.0M so won't trust that until I see the result of the switch for myself).
The only thing I can be certain of at the moment is that changing the NTE5 socket faceplate to one with built in filter and ditching the micro filters is well worth doing and that my TP-Link is a great router (though I think the faceplate change made the biggest improvement).

[#5]

One does wonder how / why you ended up on ADSL 1?