Still no refund

[crc]

I sent in a refund application to Iarnród Éireann on 12 June, and still haven't heard anything back from them.

The refund was based on the late arrival of the 6pm Dublin to Cork train on 6 June. The train was over an hour late, and I applied for the 50% refund that's available.

What should my next course of action be? Should I just send them a letter, or is there something I should / could do to 'escalate' the issue?
I don't even care about the amount of money really (€16.50), its more the principle that I am entitled to a refund, and IE appear to be acting like pigs and either won't give it to me or are making it difficult for me.