COLUMBIA -- City officials in Columbia say they've stopped paying their bills twice. Including the auditors who discovered the city had paid many people twice. The State newspaper reported Friday that the city's deputy finance director, Bill Ellis, said some bills previously were paid twice because there was no system to ensure bills were paid on time. The process was changed two months ago. Ellis said previously bills would come in and not be processed and a second bill would arrive. Ellis says the city often paid both bills. One of the vendors paid twice was Webster Rogers LLP, the accounting firm that audited the city's records and reported the problem. Columbia has had accounting problems since 2005, when it was unable to close its books on time.