Have you checked that all cables, especially the white coax are all firmly connected and finger tight? If using an ethernet cable have you tried a different cable or port on the hub?
Have you clicked on Check service status at the top of the page, and also ran tests from there?
If so and nothing else showing them you need to contact the Faults team.
You could try the text messaging service. Just send a text with a description of TV Faults to 07533 051809. Your message will go into a queue and a representative will respond to you as soon as possible.It may take a few days.
You can also call 150 from a Virgin landline, or 0345 454 1111, options 1,1 and 2 (Faults) butbest to call at 8am to avoid call queues
When calling Faults you will go through a series of questions/tests, if that doesn't resolve the problem then call back around 10 minutes later and an agent should pick the phone up
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali