I stayed (paid revenue stay) at the Courtyard Denver Stapleton in Sept 2018 as a Plat Premium and never received any platinum amenity. I did ask about breakfast at check-in and they told me it wasn't free. Looking at my bill, it has my Marriott number OK. Do I qualify under the "failed elite benefit" system?

I've emailed Marriott customer support once a month now for the past 3 months. At first, they said they'd have the hotel contact me but no reply. My emails to Marriott customer support now go unanswered.

Any recommendations on how to escalate? Do I contact the hotel directly? Am I really entitled to a failed benefit system? I'm an SPG transplant so this is new to me...