So I have been a customer of Virgin for around 6 years or so, and decided to finally have a look elsewhere.
Found some good deals from other providers so rang up to cancel Virgin. They did nothing to try keep me e.g. no mention of money off a month. I was also interested in the "Full house bundle" only to be told thats for new customers only. Shocking!
A quick superficial look through this forum will give many similar complaints, and nothing you say here will change your offer. If you are out of contract make a polite call to the "thinking of leaving" team and see what they offer. If it is not good for you, leave. Expect the same from your next provider and be prepared to leave them when your contract expires. Sadly It's the way the industry works.