A city lawmaker is blasting the Department of Education over how it monitors abuse complaints on school buses in the Bronx and the rest of the city.Councilman Bill de Blasio joined advocates Wednesday to call for legislation requiring the department give monthly updates to the City Council about abuse complaints. De Blasio says he wants incidents to be tracked more closely, investigated thoroughly and acted on appropriately. After filing a request under the Freedom of Information Act, the Daily News was told by the Department of Education that there were more than 3,500 abuse complaints in 2006. De Blasio claims education officials have told him an additional 175 cases of abuse have been discovered since the department released its figure.The DOE says it has hired investigators to probe the issue.