I need help getting a refund for a purchase I never made.

So, I recently bought the season pass, and got Vanbucks with it, and I noticed that the majority of my Vanbucks were missing about 30 minutes later, and when to see what happened, the game had automatically bought the Halloween pack without ever asking for my permission or telling me. I'd like a refund on my Vanbucks, I lost 2,150 Vanbucks.