IMC just got a little soured for me!

This will most definetly go under the Rant column but here goes.....

I've been searching the internet for accommodations for 10ish people when I came across a beautiful 8 bedroom mansion (http://www.vrbo.com/151726) so I call to check availability for IMC.
I am told it is available for the dates I want Aug 22nd - 29th, my family and I wanted to spend a week enjoy some of the great sites Penticton has to offer.
Well after getting everything arranged with family and adding a few more friends (16-18 of us in total) I call back.
Well she says as it is Ironman weekend, we can't rent it to you for the dates we've already agreed to, you have to rent it for ten days..........This is after reconfirming with them a 2nd time the dates I wanted.
So I refuse to pay for a house that will just sit there empty for two days before we get there, and now the whole Ironman experience seems a little tarnished now. Is this gouging of competitors common place because I was thinking of making this an annual event but now I don't think this will be the case.
Anyways just had to vent a bit,
Thanks