What should have been a happy celebration turned o...

What should have been a happy celebration turned out to be a disappointment. We had a 7:45pm reservation on Saturday December 16, 2017 for 12 people. We got there around 7:30pm to check in. They were rude to us and told us to go outside and wait until 7:45 then come check in. At 7:45, we came in to ask about the table, they said it's not ready yet. By 8pm, we came in to check again and they brushed us off saying it's not ready. By 8:10, they told us the table is being set up and we should wait and be patient. By 8:20, I came in and demanded to talk to the manager. When the manager showed up, I told her to give me a straight answer how long do we have to wait because we have an event to go to after dinner. She said the table we reserved is still occupied. The customers paid the bill but refused to leave. I asked her to give us another table, she said they're all booked. She suggested we should go somewhere else if we don't want to wait. I told her where can we go find a table for 12 people at that time of the day and during the holiday season. She offered us drinks and appetizers while we wait outside. We didn't get our table til 8:50pm and by that time we had to cancel the event we were going to and lost money on the tickets we bought.
It was obvious they overbooked the reservations and refused to acknowledge it. They should know our time is as valuable as theirs.