That's probably because the front desk staff were very busy. In my experience, a face-to-face encounter is ALWAYS better than a phone call. It doesn't have to turn into a confrontation, but both you and the associate can use nonverbal cues as well as the words you say to convey your messages. In addition, it's both literally and psychologically harder for the associate to dismiss you and your concerns when you are standing right in front of them instead of being a disembodied voice.

I wasn't there, but to me this would have been simple. If I encountered the room as you described it I would have walked right back to the front desk, explained there had been a mistake and the room you went to was not acceptable. If she had claimed they were sold out and no other rooms were available, I would have gently explained that was too bad and that I would take the compensation for being walked to another hotel. FWIW, there are lots and lots of Marriott properties in that area, and even though it would have sucked to drive to one of them at that time of night, it still would have been better than putting up with an uncleaned room which obviously still upsets you.