Interesting that you were blamed by management for their screw up, as I had exactly the same happen to me when they woke me up and then blamed me for not realising that the DND button did not go as far as letting them know not to phone me. I was so angry about the entire ordeal. To do it in the first place was annoying, but just apologising would have resolved it. I would love to know if it was the same member of management.
PH Sydney remains the only property I've ever gone to the GM with an issue. The only reason it was resolved was thanks to the kind folks on FlyerTalk passing me on the GM's details, as no one else was prepared to do anything.