Someone really dropped the ball here not contacting you about this at a minimum. Status or not, you should have been taken care of at an alternate property free of charge until the hotel opening day since it sounds like the hotel opened in the middle of your trip. Then you could have been moved to the hotel at a paid rate. Yes it is an inconvenience to move hotels mid-trip but if they took care of the "alternate lodging" the first night(s) and also it is nice to be the first person to stay in a newly constructed hotel so that is also worth something.

I think asking for the difference in the reserved price and what you paid at the competitor is very reasonable but I don't think you will get it. Given the lack of response from anyone about the whole thing I'm not real sure you will get anything. But with management this poor, this hotel will have a lot of other issues...