Option 1:
Take the TV back and try to exchange it for a 'Freeview HD' set. (If the salesman advised your wife that the set could receive Freeview HD signals, then it's not 'fit for purpose' and you've got the right to a full refund. Otherwise any exchange will purely be a goodwill gesture from the retailer).
Option 2:
Get a Freeview HD set-top box. (Your TV can display HD pictures from ANY external source, such as a Freeview HD box, a Virgin HD box, a Sky HD box or a Blu-Ray disk player):
http://www.argos.co.u...1&searchTerms=5322408
(NB: Ensure that you connect such a box to the TV with an HDMI cable. If you use a Scart cable you'll lose the benefits of HD).
Option 3:
Forget Freeview altogether and upgrade your Virgin subscription to HD.
Chris