Iberlin and others subscribed to the services of TCI Cablevision of Wyoming, which imposed a $2 late

Question:

Iberlin and others subscribed to the services of TCI Cablevision of Wyoming, which imposed a $2 late charge on any bill not paid when due. Iberlin brought suit against the company, claiming the late charge was for extending credit and thus did not comply with state and federal laws governing credit charges. Was Iberlin correct? [Iberlin v TCI Cablevision of Wyoming, 855 P2d 716 (Wyo)]