FTTC speed painfully slow

[#1]

Hi!
I'm currently getting an incredible 3mb/s down and 7.6 up on this connection.
The speed has been disappointingly low (~30mb/s) for the last couple of months, but today has dropped through the floor. I'm not sure if there's network issues, but I can't see anything regarding them.
Is there any idea what's happening here? And if this is just a temporary issue, would there be a way to have my line-speed reviewed with a view to helping me achieve a better speed in general? The customer that recommended your service to me is 10 doors away and getting close to 80 from the same green box. I believe 30 is below the quoted speed for the line. Plusnet even dropped my estimated speed after I paid for the service and had it running for a couple of weeks. Not sure why this happened either.
Thanks so much for the help.

[#2]

Hi there
I can see you spoke with our Technical Support team regarding this last night.
It looks like there's a external fault on the phone line that's to blame for the poor speeds.
That should be cleared by the close of play on the 27th and then we can test the line to see if there's any improvement.
Any further issues please let us know