it is the Jobcenter in the town where you live, which you must contact and ask them about the conditions for being able to get refund for the costs incurred because of jobintervies.
There can be different rules/conditions between the different municipalities (kommuner).
But the Jobcenter can help you. And if you qualify for refund, they will also help you with application form.
Anders Weber, www.a-kasser.dk