How can I request a refund for a subscription I don't want from the App Store?

I am requesting a refund for a free 1-month trial LinkedIn subscription I didn't want to keep and forgot to cancel subscription in time. I was charged today for it's renewal for $108.24. I've cancelled the subscription and requested a refund via LinkedIn and they directed me to Apple. The subscription is not affordable for me at this time, so I would like a refund please. Please advise.

[Re-Titled by Moderator]