How to bring the person responsible to administrative liability for unlawful refusal of access?
If the data user has not provided the information you have requested, in cases where such a request for access is clearly allowed by law, you can appeal to the Information Commissioner.
The Information Commissioner is a second-level body that resolves user appeals against decisions of public authorities. The user can file an appeal against the decision to the Information Commissioner within 15 days from the date of delivery of the decision, through the first-instance body that issued the decision. Also, an appeal to the Commissioner can be filed when the public authority does not decide on the applicant's request within the legal term (the so-called silence of the administration). In that case, the appeal can be submitted directly to the Commissioner.
An administrative dispute may be initiated against the decision of the Commissioner before the High Administrative Court of the Republic of Croatia. The dispute can be initiated by the body of public authority that has solved the request or by the user who filed an appeal with the Commissioner.