Fleet arena store hasn't refreshed

Maybe that's what's supposed to happen but I'm telling you I log in at least 3-4 times per day and I haven't seen Vader or Chirrut in almost 2 weeks. I've had 3 Maul drops but no Vader. I need 1 more drop for a 7 star Vader and like someone else said it seems the game knows that and isn't going to give it to me.