We have been having a swimming pool, covered separate patio, and landscaping construction done. Our total contract was in the amount of $70,000.00. We have paid a total amount of $66,500.00. Our swimming pool has several problems with the construction that need to be fixed. Our contractor makes appointments and does not show up over the past 2 months. Today, I received an intent to lein from a company that bought our contractors receivables. It says we owe $19,495.00. That is absolutely false. What do I do?