You have done what you can to test. (Ideally best to plug the corded test phone into the main/master socket and unplug any other devices on your home extension sockets so as to minimise any issues with your home wiring or other faulty devices in the house causing problems).
Ring in via mobile to log the fault or login to ‘My Virgin Media’ and run the service status tests
The forum team will respond on here but may take up to a week to reply and I don't think reporting on here is counted as an official method of logging the fault WRT any possible outage compensation claim.
If you phone in, most suggest the best chance of getting through is early at 08:00.