Bill Correctors Ltd. v. MCI case before the FCC started with Bill Correctors' complaint that MCI overcharged its customers by charging for incomplete calls (busy or unanswered) and for the time lapse between placing the call and answering of the call by the second party. The complainant sought that all such MCI customers would be reimbursed for all investigated overcharges regardless of when they occurred. Later the case was combined with other dockets where Bill Correctors complained against other communications carriers (OCCs), and FCC ordered OCCs to inform the commission of the means by which they advise their customers of the possibility of billing errors and of their credit policies regarding calls of short duration. MCI stated that in its billing practices it used the Asoftware answer supervision@ which allowed, with a high degree of accuracy, to determine the actual beginning of the call. It also emphasized that MCI customers could discuss all calls on dispute with MCI Customer Service and were supplied with information about it.