This is Hilton Grand Vacations Company and they will not take no for an answer. They can get around the 'Do Not Call" list because you are either a HHilton Honors member or have used their services in the past. Saying "No" is only considered a cold refusal and they will continue to pester you. After a bit of digging I found the CEOs email address and so I suggest people start emailing him directly. He will probably have some admin filter them first but I expect if they start getting thousands of them tying up legitimate emails, it might be worth doing.