Thanks for your reply.
What you say is a lot different from what is shown under "My Offers" when I log into my account. See here:
https://my.virginmedia.com/my-offers...gd_out_sign_in
Any clues, anyone?
David
P.S. OK, £4.60 which I am currently paying for free evenings/weekend plus the upgrade offer of £3.40 = £8.00 which is what I would pay for unlimited calls if I was a new customer, so that explains it all. Sorry for the confusion!