Recent speed drop

[#1]

In the last week or two, my download speed has dropped from around 67mB/s to roughly 25-29mB/s, and my upload from 20mB/s to roughly 14. Is there any possible reason for this, and is there any way to return my speeds to what they have been for the previous couple of years? 

[#2]

Hi there

My tests have indicated an external fault which I've raised to our suppliers now. You can monitor the progress on this ticket. We'd expect updates within the next 3 working days.