You should call up and speak to the retentions team. They deal with cancellations, however they can also look at your package and and needs and should be able to offer you a new deal. I would definitely ask what's available.
You would need to give 30 days notice to cancel and should be able to do so now without any early termination fees if you only have a month left on your current contract.
You must have left Virgin for a minimum of 3 months before you can possibly take advantage of a new customer offer.
You could try the text messaging service.
Just send a text with a description of cancellation to 07533 051809. Your message will go into a queue and a representative will respond to you as soon as possible. It may take a few days.
You can also call 150 from your Virgin landline, or 0345 454 1111, butbest to call at 8am to avoid call queues.
If calling go via the Moving House and Thinking of leaving options, then you;ll be able to speak to retentions, and hopefully find a suitable offer.
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali