My friend and I recently booked separate one-night reservations at the Delta Hotels by Marriott Seattle Everett which is located in Everett Washington, a suburb of Seattle. The reason for the stay is we have an early morning Amtrak trip to Vancouver BC to catch so wanted to be near the station. I telephoned the hotel to ask whether we could leave my car there one extra night beyond our stay since we would be staying in Vancouver one night. I told them if not we would have to cancel the reservation and find somewhere else. I also mentioned we were both Titanium Elites for Life (for whatever that is worth, which as it turns out is not much at that hotel) and I offered to pay any additional parking charges for the extra day.

The person who answered the phone, who confirmed the two reservations, said she would get back to me after consulting her manager. She later left a voice message stating we could not leave the car at the hotel a single extra day.

I then telephoned another hotel a few blocks away that is in about the same class as the Delta Hotels Seattle Everett. I have no status with the other chain but nonetheless the person who answered the phone said there would absolutely be no problem leaving the car there one day beyond our stay.
Am I being unreasonable in being upset with the Delta Hotels by Marriott Seattle Everett about this? In any event my friend and I will be cancelling our two reservations there soon but we will wait two or three days to see whether someone from Marriott sees this and convinces the hotel to extend what to me seems from the hotel's perspective a minor courtesy.