Poor speed in peak hours - losing will to live - o...

Question

Hi BT,
I am almost at the point of begging someone to help me here, thank you in advance for your time and insight. It was with a heavy heart that I departed from BE There after Sky's takeover, and invested a little faith in BT. I started a contract for BT Total Broadband 3, and received an immaculate service for the first ten days or so of my contract.
Then, quite suddenly, I started receiving dramatic drop-outs in peak hours only. As I type this, BT Speedtest reports downstream of 18.95mbps (as quoted) but by tonight, it will be down to around 0.05-0.1. This is with both a wireless and wired test, and has endured, every day, for around a month now. I work from home, and it's losing me money every night; if I restart the router then it sometimes picks up by a few mbps, but within minutes has returned to where it was. 
I have a query open with BT Technical help department who, unlike general customer services, have been very responsive and helpful! I have been sending them regular diagnostics, however no-one can yet seem to identify what the problem is. They first suggested resetting to factory settings - no change. I then ran the full diagnostics with the aid of a BT worker's call last Friday, including TAP3 and everything that comes after, and the verdict was that my Broadband is 'performing extremely poorly and that a fault would be raised'.
I found this reassuring; however another employee called me this morning to tell me BT had spoken to the exchange, and ascertained that supposedly everything was 'fine with my line'. She suggested I try testing the service using the master socket in the white BT box, however there is no response when I try this - I cannot connect to Broadband, or get a dial tone. I am keen to know how much of an issue this could be, and whether this represents a problem on 'my' side or BT's? I have tried changing filter - same result. I have also called 17070 and there appears to be absolutely zero noise on my line. 
I am at my wits' end, and constantly curse the decision I made to throw away a connection that hadn't misfired once in three years for one that is effectively unusable in the evenings/weekends. I have also recently finished a full time study course, money is short and I am slowly suspecting that I am going to be strong-armed into paying exorbitant engineers' fees to look at a connection that, with my previous ISP, functioned perfectly. This is desperately depressing; please, please could someone try and help?
 This is my current ADSL status at 13.30:
ADSL Line Status
Connection Information
Line state:
Connected
Connection time:
0 days, 00:30:55
Downstream:
20.9 Mbps
Upstream:
1.133 Mbps
ADSL Settings
VPI/VCI:
0/38
Type:
PPPoA
Modulation:
G.992.5 Annex A
Latency type:
Fast
Noise margin (Down/Up):
3.0 dB / 6.0 dB
Line attenuation (Down/Up):
14.5 dB / 7.5 dB
Output power (Down/Up):
19.9 dBm / 11.5 dBm
FEC Events (Down/Up):
0 / 0
CRC Events (Down/Up):
63 / 32

Answer 1

Hi there, thanks for your response
Connection time is short due to my testing via the test socket about half an hour before posting on here. As in the above post, there is no response from the test socket; the master socket works fine (apart from the obvious slow-down issues in peak hours). The master socket is the only one in the house, and I've used it without issue for years before switching over to BT. 
These are the requested full stats which I've just obtained (I had to restart the router again, which will explain the short connection time again!)
ADSL Line Status
Connection Information
Line state:
Connected
Connection time:
0 days, 00:03:52
Downstream:
21.02 Mbps
Upstream:
1.129 Mbps
ADSL Settings
VPI/VCI:
0/38
Type:
PPPoA
Modulation:
G.992.5 Annex A
Latency type:
Fast
Noise margin (Down/Up):
3.0 dB / 6.6 dB
Line attenuation (Down/Up):
14.5 dB / 7.5 dB
Output power (Down/Up):
19.8 dBm / 11.0 dBm
FEC Events (Down/Up):
0 / 0
CRC Events (Down/Up):
1 / 0
Loss of Framing (Local/Remote):
0 / 0
Loss of Signal (Local/Remote):
0 / 0
Loss of Power (Local/Remote):
0 / 0
HEC Events (Down/Up):
0 / 7
Error Seconds (Local/Remote):
68 / 0
PS - if you want me to leave it a while before posting stats, given the router has just been restarted, just let me know and I'll make this happen!