A person aggrieved by a decision of the administrator or whose claim has not been acted upon within ninety days after its filing may bring an action to establish the claim in a court of competent jurisdiction, naming the administrator as a defendant. The action must be brought within ninety days after the decision of the administrator or within one hundred eighty days after the filing of the claim if he has failed to act on it. If the aggrieved person establishes the claim in an action against the administrator, he shall be entitled to an award of costs and reasonable attorney fees.