Please Help! Hotel is Reneging on our deal!

I don't ask for help like this often, but it's for my buddies.

Here's the story, three of my friends and I are headed to Whistler in two days. We got a package deal for rooms and lift passes that was booked and confirmed with the hotel (Carlton Lodge) weeks ago. When we booked, their website offered it at an oddly low price even for the deal, which we called and confirmed before we booked it. The concierge at the time told us to book it and they would keep their end of it for the price we paid. Now they've contacted us and said that we must pay more or the rooms won't come with the lift tickets. We've received both confirmation of the room booking and the lift tickets. My friends fly out to meet me on Saturday and we don't know what to do. Can anyone make a suggestion? Or maybe mass e-mail them and ask why they're reneging on their deal?(little extreme?)

TL;DR: Carlton Lodge isn't upholding their end of the deal; keeping the lift tickets that we've been confirmed.