How would you be able to use it next week as an award stay if it isn't booked as an award stay? Award stays have to be reserved in advance. Although I've done same day award stays, I still had to go through the booking process.
On the other hand, it might be worth a try to call Marriott Rewards and see if they have mercy on you by cancelling the current certificate and reissuing another. Not sure what the outcome will be, but I've found them very helpful with other issues.