I was going to suggest you take the trailer home and camp in it until they get the new window in and it's convenient for you. But then I saw the part in the original post where you basically said you won't take it until it's fixed. The fact that you never took it off the lot might be able to work in your favor. But hopefully it doesn't get to that point.
Tomorrow (Wednesday) I would call the dealer for an update on what is happening. Then call the customer service number for the manufacturer and talk to them about it. Ask them if the dealer has even ordered the part yet. Tell them you are getting frustrated and need some assistance from them to get things moving. See what they say.
But truly nothing you described sounds like a show stopper and I would take the trailer and go camping.