no no.
This is not how you do it.
Call marriott first and book the reservation with them and tell them to attach the vouchers.
Then call the hotel and speak to staff to verify that you have the two vouchers attached. Hang up.
Next day call the supervisor and ask him to see if the vouchers have been used for the reservation.

upon checkin ask again the front desk as well as supervisor. Upon checkout you will be given a checkout receipt displaying nothing owed to the hotel.
In a few days you will be charged rack rate on your credit card. You will have to call back corporate and the hotel itself including the GM of the property. It will take a good 2 months, so just dispute it with your credit card...

hehe not really but I have been thru something like that before. : )