ADSL line status
Connection information
Line state Connected
Connection time 0 days, 0:13:55
Downstream 11,851 Kbps
Upstream 1,171 Kbps

ADSL settings
VPI/VCI 0/38
Type PPPoA
Modulation ITU-T G.992.5
Latency type Interleaved
Noise margin (Down/Up) 8.6 dB / 6.0 dB
Line attenuation (Down/Up) 19.0 dB / 10.0 dB
Output power (Down/Up) 0.0 dBm / 12.6 dBm

Hmmm .

Your IP Profile in the earlier speed test is correct for the connection speed. (As it was at the time).

It looks from those stats as if you have some instability. That could very well be you doing quite a lot of reconnects hoping to improve things. It doesn't! It causes the "Target" noise margin to be raised from the default 6dB, in steps of 3dB. As the stats are only 14 minutes after a reconnect, and show 8.6dB, I would think it is now set to 9dB.

Stop trying, and it should in time reset to 6dB.

However, that will be costing you at most 1.2Mbps. You are connecting at 11,852Kbps, so even when that happens it will still be under 13Mbps.

With your downstream attenuation of 19dB you should be connecting at 18Mbps or more, as you say were told. First step is to read the Ring/Bell wire and Miscellaneous nasties pages on my website. Sort out the ring wire if necessary, and see if anything else applies to your setup.