Since no one paid for the Champagne there can be no actual damages. It was a gift.
If the advertisement said ‘Champagne’, then it’s a misleading statement. To also be correct...the only real difference between Champagne and Sparkling Wine...is that Champagne has to be manufactured in a particular region of France. If you don’t make it there....it can only be Sparkling Wine. Otherwise, it’s the same stuff.
If you imported Champagne into the US or Canada....it wouldn’t be a cheap deal.