I have been having the same issues as outlined here. I called last week several times and every time someone passed me from retentions to cancellations, they asked for some security details, put me on hold and then hung up.
Since I am not recieving the service I am paying for I will be cancelling my direct debit unless someone from virgin contacts me and advises me otherwise.
This is absolutely shameful service - the service is no longer required and yet Virgin puts every obstacle in the way to stop the consumer from ceasing money from flowing into their coffers. I would suggest everyone follows the same approach outlined here - cancel your direct debits. Virgin clearly do not have the staff to deal with cancellations let alone chase for unpaid bills.