Originally Posted by
EuropeanPete
You can understand where they're coming from. As they note, Twin beds are not available in the category you booked. It wouldn't be unreasonable for them to offer an upgrade early for Diamond customers, but it's also not unreasonable if they pointed out that upgrades are space available only. Presumably there's a reason why you booked a King bed room when you wanted a Twin?
For a Diamond at a luxury property, in Asia no less, it would definitely put me off if they responded as they did. (The poster clarified why only the King room could be booked)