Good morning alanaliddell,
We understand that sometimes these charges occurred without us knowing how to really got subscribed, but no worries, I have found a topic that will likely help you with your concerns.
Most likely you will receive your refund in the original payment method. If you had money added to your Apple balance and it was deducted from there by the time of this subscription, most likely they will refund it back there. Now, in the event the money was taken from your debit, credit card or bank account, it depends on your financial institution when the money will be effective back on the account. I will recommend you contacting them to see their processing times.
This link can help you as well with some other questions you may have about refunds through the App Store and their policies.
I hope you found my answer a bit helpful (: