I accidentally upgrade my iCloud storage plan, how can I get a refund?
I tried downgrading my current plan but it didnt work.
You can request a refund on certain App Store or iTunes Store purchases within 90 days of the purchase date through your purchase history. Limitations apply. See the Apple Media Services Terms and Conditions for details. If your problem is with a recurring charge, you can cancel your subscription.
https://support.apple.com/en-gb/HT204084
Hope this helps