I’ve disputed a breakfast charge from the Westin Pasadena on my credit card after trying to call the property 3 times, the “accounting person” was never there and never called me back. The final time I told them I would just handle it with my CC company. 5 years later and I’m still a Bonvoy Ambassador.

Since you’re not disputing a “Marriott” charge per se, but rather whatever franchise owns the hotel, it’s up to them how they want to handle it. The Westin Pasadena actually apologized to me and didn’t fight the dispute