The only way to unlock the phone at this moment is through Factory Reset. Turn off the phone then press Volume Up + Home + Power buttons at the same time until the Android logo appears. Once you're in the Recovery menu, use volume buttons to select Wipe Data/Factory Reset and confirm the operation with the help of the Power button. The phone will reset and it should be restored to factory defaults. Your settings, 3rd party installed apps and accounts will be deleted.
