Double booked for our stay

Our company had made a booking at Louise Terrance for our group as we had a very late function in Sandton. This booking was made by one of our reservation ladies quite some time before the actual function and paid for as most of us had come from far to assist during this function. After finishing at 11pm we left Sandton for the hotel. Upon arrival we made our way into our room with the keys that one of the members of our group collected earlier on in the day. When we entered the room there was a lady sleeping in our room who started screaming. We then closed the door and made our way back down stairs and tried to contact the owner/manager to find out what the problem was. We contacted him for almost an HOUR on numerous different numbers and could not get through. His phone didn't't even have voicemail so I couldn't't even leave him a message to explain our situation. At 12pm we gave up and started phoning other hotels to see who could accommodate us. We eventually found a hotel in Sandton and had to pay a ridiculous amount of money as this was the only hotel that had an available room and that answered their phone. WHAT RIDICULOUS SERVICE!!!