I am so sorry about your recent reduced speeds. My tests confirm that peak time Internet usage is high and your CMTS is struggling to cope with the load. I have escalated this to Networks for inclusion in network upgrade plans.
I shall post the fault reference as soon as they get back to me and I have fully noted your account with details about this.
The fault reference is F005214077. We should get a review date by the end of the week so feel free to post for updates.
In the interests of honesty though I should add that the review date, when we provide it, will refer to the progress of the pre-upgrade work and may well be replaced with another if the work is not yet complete. This type of issue does tend to have a lengthy lead time sorry.