An attorney for several city councilors in Central Falls who are pushing for the departure of the state-appointed receiver has indicated that court-ordered mediation has broken down. Lawyer Lawrence Goldberg said the mediation overseen by former state Supreme Court chief justice Frank Williams failed. In January, Superior Court Judge Michael Silverstein ordered the sessions to try to resolve a dispute over the end of the receivership. The state revenue director has said the councilors must attend workshops on the five-year recovery plan approved by a federal bankruptcy judge. The councilors say they are not required to do so.