Unfortunately the original quote was wrong, and you should not have been offered that price
The VIP bundle with two V+ boxes is an extra £10 over the standard price, so would be £96 per month. (when paid via D/D and on e-billing)
The reason people cannot do anything is because there are no discounts off the VIP bundle, so there is no way of giving you the £90 price
---------- Post added at 17:52 ---------- Previous post was at 17:45 ----------
As for what to do next, if you are not happy with the way Virgin have treated you, ask for a 'Deadlock' letter.
This would then allow you to take the matter to
CISAS the Alternate Dispute Resolution service Virgin Media work with