Sun International is always fully booked!

I am a platinum card holder at Sun International. Everytime I want to book a room to stay at SunCity or Carnival, they are always fully booked. It seems like the rooms are kept for certain people only. I rather go to other casinos then go to Sun international. I'm really disappointed at the service sun international provides even over the phone. The moment you ask for the availability of a room the consultant will immediately request the status of your card and thereafter inform you that there is no availability. Service provided by Suninternational 0/10 - Thumbs down!