I have no idea why your gratuities increased in price, however, I do recall some posters on CC having their Silver Spirits Beverage Package prices increase upon receiving their final invoice -- after having paid for said package at an earlier time.
As far as enjoying alcoholic beverages in public spaces, we have enjoyed their beverages and our own beverages in all sorts of public spaces on the ship, so I think that is erroneous information. We have never been charged a corkage fee and until now, I have never heard of that on Viking. If that is the case, we do carry our own corkscrews -- in fact, a couple of them.
If you don't like the answers you are getting via chat or telephone, chat or call back until you do. Such are the workings of the LA office. No worries, IMO.