If champagne is specified, we have always had champagne. If anyone doesn't gwet it, then they should ask for it.
We have always had the correct number of mini bar bottles and if you don't get them, then just make a request. No big deal.
Cunard pricing is fluid. It can go up and down for the same accommodation. I have never seen a UK price promise.
Website is well known for its 'foibles'.
You have obviously concentrated on the glitches. Smooth runnings don't make headlines. If there is a problem, and it sounds as if you';e in QG as you're talking champagne, then just ask the Butler.