It's standard for these days for CEOs of large public facing companies to have a public email address and a private email address. Email to the public address is directed to a high level complaints team. That's certainly the case where I work and likely the case in Virgin. I've had problems with Amazon recently and had zero success via their customer service people - complaining to the UK CEO yielded immediate results.
There's some contacts for Virgin Media on CEO Email and other similar sites.