How can I get a refund from Apple after Robokiller auto-charged me $138?

The app robokiller to help prevent unwanted calls and scam as well. Im serious averaging 50-60 a month. We went with the 7 day free trial only and did not know the subscription fee was set at yearly. Once the $138.00 was taking out within hours we made multiple attempts to apple for refund. They will not and now case is closed. This app even blocked known contacts and other important calls from our hospital. I didn’t find the app very useful and knowing the third party open windows was a concern to.

any suggestions or am I out of the refund?

[Re-Titled by Moderator]