I sent an email to Courtyard Bangalore Bandung (Their reservation email is [email protected] if anyone care) about amend my reservation.

The property did respond promptly and address the issue straight away.

The interesting part, I receive an email from Marriott right after I sent the email (The property reply few hours later). A survey about my experience with email communication with Marriott property ....
It does ask about how satisfied I am with the resolution given by the agent and so on.

And also there are form for writing feedback.

Still dont understand why Marriott hide property email address from their website