The official answer is contact the "Standards in Public Office Commission" tel 01-639 5666 . they're in Leeson st Dublin and are supposed to enforce the law dealing with such things as civil servants are supposed to deal with members of the public "sympathetically, efficiently and promptly". You can google all this.
the unofficial answer (and I'm a prejudiced old man) is that civil seRvants will rarely give a definitive reply if it is anything but bog-standard rules.
If you have asked a question that cannot be answered exactly as per the rules - i.e. that would involve someone giving an interpretation or an opinion - then forget it.
Even persistent writing in recorded mail won't elicit any response. Even if you are a director of a trade body (as I was) it won't help much. But...
.. formally complaining to the above body ,especially on a solicitors letter (stating that "due to lack of guidance/information from xxxx our client is uncertain what action to take resulting in loss of earnings etc etc and it is therefore imperative ,as per the relevent statute that his/her query is dealt with promptly") did work.
Having said all this maybe first making a phone call and getting a name of someone in the dept to whom you are writing may help.