In Tenorio v. State, 261 Ga. App. 609, 611-613 (3) (583 SE2d 269) (2003), defense counsel's investigator was made aware of potential alibi witnesses at the defendant's place of employment, but simply shirked his responsibility to locate and interview them and then billed for investigatory services that he never performed. 261 Ga. App. at 612-613 (3). The Court held that the investigator's total failure to exercise any diligence in investigating the witnesses was chargeable to defense counsel. Id.