My mother bought a double wide home. Was lied to about the reason they needed a copy of her deed & com put a lien on the property

My mother was lied to about why the mobile home seller needed a copy of her mother's will showing my mother's inherited, Surveyed piece of land. They told her that they needed a copy of it to see where the double wide would need to be set up. My mother recently passed away and I looked at the contracted and noticed that they had marked that they has a "security interest" in the land. I was present at the signing of the contract and the only living heir. I have no executor or administrator over her estate. I also had a real estate agent pull the deed of trust on the land and the mortgage company had put their name on it without our knowledge. I want to keep the land and don't care about the double wide. It is not on a perm foundation and is stated as Personal property in the contract. Can I sue the mortgage company for this in Tennessee? The mortgage company has had a class action lawsuit on them before. What can I do to keep the land?