You have evidence of an agreement (12 months of payment at $500/month) and forbearance (you did not force the sale of the property). You can enforce the verbal agreement, but may be subject to a defense under the Statute of Frauds which generally requires that any agreement pertaining to real property (I assume the lien was on real property) be in writing. The analysis of a Statute of Frauds defense can be complex and varies state-to-state. I'm unclear about how you came to be able to...