Dissapointing and sad

I made a booking at this restaurant in the first week of January for a 60th birthday dinner, I watched as they wrote my name and number and how many guests in the book. When we arrived there for the party there was apparently no booking!!!!! The book did not have my name in it, so I do not know which books they have or who does these types of bookings. When I booked they called a young guy who they said was in charge of the bookings, we even went to look at the room that we had booked to check that it was big enough and had aircon, which we were told was working. On the 14th January when everyone had arrived they had put us at another table as they said the aircon has never worked in the private room we had booked plus they did not have the booking. It was an incredibly hot day due to the heat wave we are experiencing so we took our decorations and left as this was unacceptable, how can you run a restaurant and LOSE the booking? It was terribly disappointing and we then had to phone around to find a restaurant that could fit us in asap for a group of 10. I am so disappointed in this as a special birthday was totally ruined due to *********** staff and no managers to be seen or found.