Comments from users over recent months suggest the CEO Complaints team have been disbanded or otherwise reigned in. You'll have to take you chances by trying to speak with Retentions, unfortunately that means "playing the game". Phone up and ask to cancel, that should get you through to retentions, although performance is very variable at the moment. If they can't give you a deal you like, tell 'em you're cancelling. To set expectations, VM performance on cancellations has been utterly diabolical lately....
The best price you can get from Retentions will be essentially driven by roughly comparable deals offered by other companies, not by what you paid last year, not by "loyalty" or fairness. So check on price comparison site, and know what you could be paying with EE, Sky or other companies, quote that to them.
