Sun international cancelled my reservations and did not give me a refund

I am a platinum card holder at sun international. I have spent hundreds of thousands of rands to earn this platinum card benefit. I had an experience at the wildcoast sun on 3 February where my sister had checked in using my card. No questions were asked as to where was i she checked in. The next day 4 February when she needed to change rooms that is when Nokwanda saw it was not the correct cardholder and requested for me. I had already left on the 3 February. After over a month the security calls me at 20.00 on 11 March tells me i am banned from all sun international casinos. No warning ,nothing in writing and i am banned. Thats how little sun international thinks of their clients. Then the damn audacity to cancel all my bookings that were made and paid for in March for the school holidays. No refund was made and no communication as to my reservations being canceled. I have nothing in writing of being banned. Sun international must remember that they are not the only casinos around. To treat a platinum card holder with such disrespect Disgusting