Slow speed after account error?

[#1]

Hi there,
About mid day I started getting auto linked to the 'plusnet were unable to take payment' page, a phonecall with customer services confirmed I had no outstanding payments and he was not sure why this had flagged on my account, and instructed me to click carry on as normal.
Anyway, since then my net has come to a crawl, difficult to even surf with speeds at around 500k. Nothing has changed from my side, not even been disconnected, still synced at 15000ish... I'm wondering whether something bizzare has happened to my account in respect to throttling for usage or something? Seems awfully coincidental that the account problem happened at the same time!
PN Profile is 13mb
BT speedtest:
Download speedachieved during the test was - 496 Kbps
For your connection, the acceptable range of speedsis 4000-21000 Kbps.
Additional Information:
Your DSL Connection Rate :15028 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 13000 Kbps

[#2]

Still having issues since the account weirdness!
Download speedachieved during the test was - 1180 Kbps
For your connection, the acceptable range of speedsis 4000-21000 Kbps.
IP Profile for your line is - 13000 Kbps

[#3]

Hi t0mt0m,
I do see the poor throughput but on my checks but all other line checks are passing. Have a look here for some troubleshooting tips.
Jojo

[#4]

Hi Jojo,
Checked all the usual stuff, from laptop and desktop. A re-sync in the early hours seems to have resolved the issue... strange one for sure!