5th wheel popped out of hitch

The lock was just hanging there... We did use a lock going to a clip. We have learned a lot through this expensive process. I appreciate all the comments and help. Learning more every day. Our friends have the same hitch no washers. No one could give me an answer that is why I went searching. My husband does the outside work but I wanted to learn everything so after he is done we go through the process again so I can learn. So now I have more steps in the process to make sure that everything is set properly. We have a checklist for inside and out. The trailer is at the dealers now getting an estimate. We have called three days in a row with no return message. So I guess tomorrow I will be calling every hour. I am trying to make sure that they have done the estimate and if I can't get any help then we will pick it up and take elsewhere. I think it is rude not to return a phone call even if you have no information.