If they brushed you off meaning they don't want to accept whatever offer you presented to them so better stop chasing them to accept that since provably the result will be the same. Maybe they don't want to deal with people asking huge demands so maybe try to deal with other casino then try if they can give you appealing benefits which you think fair to you. But those casino you mentioned is really good already and  just wondering why you look for another casino while you can continue to deal with them since you can continue to bet without having any problems. But its your choice maybe you are going after for some bonuses so good luck for trying and let see if there are other casino can give your demands.