If you hired the firm and the scope of work concluded, you should receive a completion of services letter. Perhaps as important as clarifying when the firm has not yet been hired is clearly communicating when the representation has ended.  A completion of services letter thanks you for allowing Keith Law to represent you and clearly indicates that the representation has come to an end. 

If you receive a completion of services letter and you have any questions or concerns you should let the firm know so that your questions or concerns are fully addressed (as you should at every stage of the representation).