We once thought we lost our card before a trip, so we called and they told us it would be a $25 card replacement fee. It turned out that we found the card, so we didn't have to do this.
But this was a couple of years ago before they switched to the new card that is like an AP, and that can be picked up from Guest Services. It's possible that now they can track and cancel the old card and give you a replacement. (like an AP) I'd suggest you call on Monday and ask.