Looks like you've got some upstream noise issues, and downstream is particularly affected by noise ingress of signals in the 220-230 MHz range. The downstream issues are probably due to DAB radio broadcasts. Assuming you haven't got any DIY coax modifications, then it's possibly a damaged cable or poor joint, or it could be a poorly fastened coax connector on the lead between the hub and the wall box.
Have you checked that the coax cable is undamaged (and unkinked) and the connections are secure with the securing nuts done up finger tight?
If that's been done, then you'll need a technician visit, and in that case wait for the helpful forum staff to advise as the telephone agents won't have clue what you're talking about.
I phoned the number you gave and the recorded message told me that there is indeed a very complex problem in my area that Virgin engineers are working very hard to fix and it may take longer than normal.