Following up on this now and people's comments and questions.

My original booking was with an AMEX platinum.

I haven't named the hotel because I didn't think it was necessary but if people want the info then after my stay I will share it.

I can tell that some of you have never worked a customer facing role in your careers.

Looking at the Google Reviews of the property my experience is not unique and many have complained about the same experience I had. I agree with the earlier comment that the hotel was looking for an excuse to cancel and replace the room at higher rates.

I called Hilton corporate yesterday afternoon and explained the situation. The woman who answered was wonderful and understanding in total contrast to the GM. She couldn't get me the room I booked but told the hotel to upgrade me if available and comped me a moderate amount of points. It is not ideal outcome but I think it helps that after nearly 10 years as a Hilton member I have never complained about anything before.