My mother in law purchased a business from my father. She had my husband to run the business. She took out a business loan as the 100% guarantor and 100% owner. We were not aware of this loan debt. We did not sign any paperwork at all. Now we have been served with a civil suit, in which the collection agency that purchased this from the original creditor hasn't shown any proof as to the validity that we owe anything. And this was done according to my mother in law, almost 6 years ago. What are our options?