A client requested technical support not related to a specific project. the technical assistance is a T & M type billing for service ticket support. Once we completed the work, we send a T & M invoice with data on what was performed. The client has net 30 day terms. In this case, he refuses to pay for no other reason then he did not think he should have to pay due to the fact that they would be updating their system at a later date and would call us at that time. We did provide a project proposal for that system upgrade, but he decided not to do the project. At the end of the day, he still refuses to pay for the service call. Is there any recourse via a lien?