Sticking to the facts presented in this particular case, I totally support the Big Guy here. The OP caught the FD person in a lie. The OP had to go out of his way to claim what was rightfully his and he did all the right moves in advance in the system setup by Marriott. And the room magically appeared!

It matters not what chain told the lie or what your chain preferences or posting history, but a lie is a lie.

As exclusively a Marriott PLT, the sad part is that I am used to hearing NO frequently (a CL room, a room I've stayed in the past, a view, a balcony, a request to be moved or placed on an empty floor) and the "we're sold out" card is often used. I'm not demanding the impossible, just inquiring of something that might afford me a better nights sleep.

Stories like this confirm what I've felt all along, a decent percentages of denials are outright lies because the FD person doesn't feel like undoing your preselected room regardless of your preferences and pre-sent note requests.

I agree with the BG's point - we are so used to being lied at at times that we don't even blink.