The number listed on Marriott.com will get you to a live person.
1 801 468 4000 (8:15am - 9:00pm, Monday - Friday, US Eastern time)

My wife used that number and recently spoke to a Marriott rep named "Paula G.", who asked us to FAX a copy of the marriage certificate to a special FAX line: 1 801 832 4333. This is not the general-purpose FAX number listed on the website.