Usually as HH Diamond I get upgrades quite frequently and also usually the recognition works well.

However, this situation happens once in a while:

- on the day of check-in when looking at Hhonors.com, my room has not upgraded
- 5 minutes before check-in, I can see online that there are PLENTY of rooms available (executive, junior suites, king suites, you name it)
- at check in they don't mention any upgrades (but DO recognize that I am Diamond)
- I then ask whether an upgrade is available

Then I get usually a reply like:
- Sorry, we are fully booked.
- Sorry, there are no upgrades available.
- Sorry, we cannot give you an upgrade at this time.
- Sorry, [Insert a lame excuse]

If there clearly are plenty of rooms available then it almost feels like an insult that they tell me that rooms are sold out.

1) How do you guys handle it?
2) I am considering to test this and demand to talk to a manager in this case. Just to see the reaction and how hard they stand on it. Have any of you tried to escalate in such a scenario?
3) According to HHonors T&C, it says when room upgrades (including suites for Diamonds) are available upon availability. How do you guys interpret the word "availability"?