I'd like to request a refund from an 'in app' purchase ...

I purchased a 'phone' from 'Hushed' a few years ago. Recently I was sent a message from a company that requested I text back with a word to show my online attendance at a forum. As I live outside the US, I gave them my Hushed number so they'd be able to message me, which they did, but I wasn't able to message back. I looked up Hushed online support, and they said that I'd need a 30-day account to send sms messages overseas, so i promptly purchased a US $4.99 new number in app. I later found out that it doesn't supply sms for 'short-coded' numbers. Here's what Hushed said: "Please be advised that Hushed does not support shortcode messaging at this time." I therefore wrote to them requesting a refund. They replied that "Hushed do not have access to your iTunes payment information (and therefore lack the capability to refund you directly), as per iTunes' policies for app developers." This leaves me in a quandary, because iTunes doesn't appear to have the capacity {via its drop -down menus} to offer in-app refunds. So what do I do?