If they have accepted and used your title search as the basis of the closing or issuing title insurance commitments/policies...they have waived the arguments about errors. The title search and the information you report therein remain yours until they pay for it. Tell them to return your property to you along with any copies they made of the searches. You have the right to know if the transactions for which you performed the searches closed using your searches. You would be well within your rights to demand answers to this in pretrial discovery. If you you begin litigation you would be able to demand non-privileged/non-confidential copies of the title insurance commitments/policies to determine if your search was used to determine exceptions to coverage.

If they waited until you demanded payment to claim errors...their excuse for non-payment becomes highly suspect. It would be one of the areas into which you would be able to inquire on cross examination as well as inquiries as to whom they complained about theses errors and the dates on which complaints were made. If there were no errors...it is usually pretty easy to establish the claim as a pretext for non-payment. Demand an itemized list of the errors they claim exist. You will have the right to do this in discovery by way of interrogatories and a request for production of documents when you go to litigation. If they claim that payments have been made you will also have the right in pre trial discovery to demand production of all canceled checks and bookkeeping records which substantiate the payments.