ADSL speed died but speed test says 15+mbps?

Our internet speed has died totally and having trouble even loading internet pages and yet when i did a speed test i get a 20ms ping, 15+mbps down and 0.8 upload speeds.defaulted the dynalink router twice with no better performance...any ideas?we're in Tauranga.

Line Mode

ADSL2+

Line State

Show Time

Line Power State

L0

Line Up Time

00:16:42:54

Line Coding

Trellis On

Line Up Count

1

Statistics

Downstream

Upstream

Line Rate

18300 Kbps

1021 Kbps

Attainable Line Rate

21360 Kbps

1021 Kbps

Noise Margin

11.7 dB

13.0 dB

Line Attenuation

14.5 dB

8.3 dB

Output Power

18.2 dBm

12.4 dBm