Beware Goldorak, I did 2 separate bookings at one place for the same night after the IT changes last year and had a similar issue (prepaid booking, non cancelable) and even called the reservations and the hotel to confirm the bookings were ok, and it was all good. When we arrived at the hotel there was no sign of our bookings and we were kicked out of the hotel whilst trying to sort it out on the phone with Accor CS (that took almost 2 hours). They did finally accept to reinstate both bookings as a goodwill gesture as I am a platinium member... A complaint to accor CS after the fact got a personalised apology.