How do I lodge a complaint against a public authority with regards to my FOIA request?

1.    You can complain to the Office of the Ombudsman.
The Ombudsman may undertake formal or informal investigations and actions to assist in resolving the complaint. A Public Authority is not obliged to comply with the suggestions made by the Ombudsman.
2.    If the applicant’s first attempt to seek resolve fails or is unsatisfactory, the applicant has the right to apply to the High Court for judicial review.