Hospitality, my foot!

I wanted to book an event at Grandwest. I recently read newspaper reports that Sun International gave a big event an ultimatum to drop an artist from its lineup due to something the artist said on a seperate platform many years ago. As I was going to invite some industry leaders and did not want to cause them the same embarrassing public treatment, I had a few questions from Sun International, which I am constitutionally entitled to the answers of. Mr Andrew Dietrich gave me a phone call, in which I could here an angry tone, and part of his words to me were "...so I can figure out what you are on about...", not exactly business lingo, nevermind in the hospitality industry. He refused to give me a straight answer to my very simple questions, and his last email to me told me he had no intention of answering. I would imagine Sun International has policies in place to vet the suitability of people part-taking in events, and I simply wanted to know what guarantees they could give me that my guests will NOT be treated the same, and what background checks are needed to ensure that my guests pass. I asked if there was a ban list, or whether Sun International seeked out a single person for political posturing. Sun International refuses to answer.