My boss denied my vacation to play WoW Classic at launch.

VENTING, apologies.So I did not take any vacation in June or July and decided to take 3 days off before Labor Day (so I would have Wednesday-Monday off). I asked for the 3 days off fully planning on only playing WoW and being involved with the launch and everything. I have over 30 days saved up of vacation and this is the slowest part of the year for my position. I even rearranged my living room last week to make a gaming space.My boss: "I am denying all vacation request until at least the end of September".REALLY? You couldn't have told anyone about your plan to deny vacation until I requested it? There is no business reason that I need to be at work on those dates. So now I must wait until October, my busiest time of the year, and you damn bet I am asking for a full week off. I will have close to 40 vacation days at that point and she will damn well approve it or I'll be headed to HR.