Nicely done, sophiegirl. As I repeatedly tell others (who never seem to listen, perhaps due to the rarified air up there in Pasadena), the only true way to speak and be heard is by voting with one's wallet.
As a fellow Marriott fan, however, who has also had occasion to actually pay for a suite, I do hope that you write a letter to Marriott corporate. The treatment you've received is inappropriate for any customer, let alone a platinum. They need to know that the process has broken down at that location.