Release of Lien

We bought a New Mobile Home in 1998 & moved it on my Property. We used a Finance Company out of Houston, Texas to Finance our Purchase of a Water Well & Septic System. We paid the Loan off within 5 years. That was about 13 years ago. Now I am selling my Property. The County Court House said they had a Lien against the Property & well & septic. That no one ever Filed a Release of Lien Document with them. I knew nothing about this until the Title Search. Its been 13 years since we Paid the Loan Off. We never recieved any Release of Lien Document. Was never Notified at all. Now I have to Resolve this matter to sell my Property. The Company was Water Financial Usa at first, then they sold out to JPT Financial Inc. I have a phone# & Address but no one has answered when I call. What am I to do. The Loan was paid in Full 13 years ago. Why is this Happening. And what do I need to do to Resolve this Matter. Thank & Appreciation for any Resolution. God Bless