One word...TwitterI reported them to ComReg! I cancelled my account in August giving the requisite 30 days notice. A week before the contract was due to end - I got debited a full months price. They assured me that it was a system thing and it would be refunded on the next bill. Anyway the next month there was a credit on my (now dormant) Virgin Media account. I waited for it to appear in my bank. I contacted them in early November asking when would I get the money back - And they were "Oh - you needed to ask for it to be returned!"
So I asked for it and they said they'd send a cheque to my bank. No sign of it - They then told me I had to chase my bank - as it was now gone from their accounts. I had no evidence of the payment. So ultimately i reported them to ComReg and chased them incessantly. I finally got my money back in mid January - 5 months after I cancelled my account and 4 months after the contract end date.
Effectively - they would have held my money in their accounts for ever unless i was diligent on checking for its return! Blatant theft by deception- and thats what I reported to ComReg.