What are our rights if the previous owners came to the location of the camper and took trailer back to their home without telling us?

First, you must look at the lease and/or any other written agreement between you and the prior owner. Unless you have specifically given him/her/it/them the right to come and do a self-help repossession, they have likely violated a number of laws. (This is if the trailer is 'real estate' rather than a 'motor vehicle.' You should hire a lawyer to tell them to return the mobile in exchange for your immediate payment of any arrearage-and that they are open to a lawsuit if they refuse. You could also get it back through the bankruptcy process, but that should only be considered if you already have a pretty heavy burden of debt-AND if you can file your within a strict 90 days from the date they took the mobile.