A few weeks ago I arrived at the Marriott Munich around midnight on a prepaid reservation. After some keying and a switch from the normal checkin staff to someone else (the night manager), I was informed, that they had no room for me and had a room some kilometers from there in a different hotel.
I refused as I was there with several coworkers, who had checked in one day before and we had to leave early the next morning.
Next thing they offered me was a roll in in one of their conference rooms, without shower or toilet. Finally I agreed to share one room with my coworkers and got a small roll in at 1 am.
The night manager first offered me two nights in Germany for compensation, after some bargaining it were 2 nights international.
The next morning at check out they tried to give a voucher for two free nights in their hotel ! I asked for the manager and he said he would take care for it.
Of course I did not hear from him. I contacted the hotel after a few weeks and got the answer that one voucher was mailed to me for one night (which it was not). I insisted that the deal was two free nights and they finally agreed and offered me 80k points and said they would contact me for my MR#, so I waited again for four weeks and nothing happened.
Then I sent them my number and finally a few days later the points showed up.
I think this is incredible as the room was already paid for and they did not care about the problem.