Hi Nirvanayoung, welcome to Flyertalk and sorry it isn't under better circumstances.

I can give a counter example of a Renaissance hotel I booked recently (in Malaysia) where the only rooms available during booking were twin beds, and me noting in the small comments box I'd prefer a King bed brought about a change of room a few days before the stay to a room with a king, plus a bit of an upgrade (note have stayed at the hotel once before and am Ambassador). I use this as an example of another hotel doing what is right and creates good guest kudos - don't judge an entire brand by one bad example. In this case I feel the hotel you were staying at is making up their own policy and, as others have said, one best avoided if you can. It is a shame that Marriott customer service is so unable to address this, but there have been lots of examples recently of their poor first level of support doing a terrible job of understanding policies and procedures properly. Only a sharp email or letter to more senior people, or the likes of the lurkers (social media representatives of Marriott on this forum) will change such behaviour.

So, I think you did the right thing to cancel as this sounds important to you, and only through consistent rejection of this type of treatment will get the message through (and it isn't just a misunderstanding or poor English on a text message, which it seems not to be in this case). You can feel free to name and shame the hotel here/on tripadvisor so others are aware when they consider staying there.