Time Ford Ka 2001

Hello, good afternoon, I have a problem I have a 2001 Ford Ka as soon as I repair my head and if I stay well but I told the mechanic to leave very little oil to change it the thing was that for the same oil the camshaft did not work well and that caused the rupture of a pulley screw where the chain passes but I need if someone can help me as I put in time again the car. In this way the piston 1 above and I move the camshaft but I do not find the time so that I can light someone I help me thank you very much I leave my email thank you very much it is I will thank you very much byy