It is possible that the hotel is not aware of your booking. I know that bookings made on the Marriott website are in Marriott's reservation system but the hotel is not aware of them until a few days, weeks? upfront. I don't know the exact period here but I know they're not directly loaded into the hotel's system the moment you make you booking.

So my suggestion would be to (also) contact Marriott to solve this out.

I don't know about your CC payment, for me personally I never had any Marriott hotel pay me up front. I hardly book any prepaid rates but the ones I had with Marriott were never actually paid upfront despite the rate being a prepaid rate. I bit strange and at first it caused some confusion at my site as I taught they were going to charge me a second time at check-out.