I got an official response after I queried them on the service charge imposed on my redemption booking. I am miffed because I had been communicating with the hotel earlier via email and nobody bothered to tell me. Anyway, I've switched out of RC Tokyo to the Westin Tokyo, after I realized Plats don't get breakfast here, which is important for me.

"We have currently faced a systematical error for a few days and indicate the wrong service charges online. We would be pleased to confirm with you that your reservation is reward points redemption stay and there will be no extra service charge occurred. Kindly disregard the service charges which are put on your reservation until the system gets fixed and the charge is removed. I am not sure about how long it will take us to solve the problem, but we are trying our best to do it as early as possible. Sorry for the inconvenience we cause you. We will appreciate your kind understanding and patience. "