Sorry you had such a bad experience. We have a lot of good folks here that can help out with most of the questions that you have. If you let us know what brand and model the trailer is there is a good chance someone on this forum has the same one and can give you a lot of insight.
Everyone says you should not have accepted the trailer but that is behind you. I would give a call to the sales manager and let them know of your experience but at the same time you should look forward to enjoying the new toy and let us all know how we can help to make you comfortable.