Challenge of a planning decision should be directed either by judicial review through the Courts, or, if on the grounds of maladministration through the Public Service Ombudsman for Wales (PSOW).
Os ydych am herio penderfyniad cynllunio, dylech wneud hynny naill ai drwy adolygiad barnwrol drwy'r Llysoedd, neu, os ydych yn herio ar sail camweinyddu, drwy Ombwdsmon Gwasanaethau Cyhoeddus Cymru.