I am fairly certain that DS is correct. They can only file a lien. If you ever try to sell your house, they would get the first proceeds. Something sounds very fishy about this to me. I would contact either a lawyer, or maybe the TV station to see what they "advise". $11,000 for a blue tarp sounds completely wrong, maybe that's why FEMA wouldn't pay. Good luck!
If you want to contact the proper authority to protect everyone, that is the attorney general. I also think the media might be interested. Forward your post to the TV and newspaper. You might be interested in knowing that you can get them to stop bothering you. Reply in writing that they are not to contact you again invoking the Fair Debt Collection Act.