I stayed at the Dallas/Fort Worth Airport Marriott as I had an overnight layover between flights. I have over 170 nights staying at Marriotts and feel I know the brand well. This stay was by far my worse stay ever and no other stay even comes close. What made it worse was the no communication with the property directly and the frustration trying to deal with Marriot directly. Living near a small market airport is challenging meaning we have little options for direct flights and often have long layovers sometimes with overnights. I travel a reasonable amount and feel my expectations are not high. When I got into my room it looked pleasant with standard Marriot décor and I was satisfied. The room seemed very muggy, it was also pretty warm, so I turned the air on to cool it off and went down for dinner. The restaurant has a very limited menu but what I ate was very good and the service was excellent. On return to my room, I quickly got ready for bed as I had my alarm set for 4:00 AM to catch the shuttle for my very early flight. In the morning, I again noticed how muggy the room was and opened the curtains to see if maybe it was raining. Instead of rain I was greeted by a wall and window with major water damage (pictures attached) including large areas of bubbled paint and black coloured mould. Tests need to be done to see if it was “black mould” but it was mould and was black coloured. There is no doubt this damage was many days if not weeks old and no way that cleaning staff would not be aware. I had to get to the airport, so I left and went there but after check-in contacted the hotel by chat and asked to be contacted directly by the hotel manager as I have never stayed in a worse room. I was assured I would be contacted. I gave them my contact information. After a day or so went by I went into the Bonvoy app to see if they contacted me there and I noticed I was refunded for my stay and given an additional 5,000 points. I was now again travelling and busy so I contacted Marriot through Facebook explaining the situation, they asked for details, and I gave them my information including my Marriot number and that they could see in my account the stay and the refund. Thy wanted more specific detail so I gave them the hotel name and the date of my stay. They said that wasn’t enough to verify I was who I said I was, I felt fine, just contact the holder of the account then. After a bit more back and forth I became frustrated and left the conversation to then do this review, I would have preferred to just speak directly to understand how such a room would ever be sold. I am not a fan of doing reviews like this. Later that day I was again given more points. I would still like an explanation, but I see now that won’t happen. I have some other issues calling the operator from the airport and less than friendly check in that would normally hardly even be noticed by me. The shuttle drivers for both my transfers were fantastic, friendly and very hel