Thanks for the encouragement. They actually showed back up today to pick up the rest of their things and I had just changed the locks. The Pay or Quit Notice I gave them said they must pay or vacate by March 20. I was out of town so they got a few extra days. They called the sheriff's office when they couldn't get in and the sheriff sided with ME! It felt like major victory.
So as far as I'm concerned they aren't getting anything back. If they try to sue I will countersue and garnish their wages---which I may do anyway once I get quotes.