I have never used even close to 5GB storage in iCloud. However, I have been upgraded without my knowledge and billed monthly. I cannot downgrade until the end of my subscription, which I never did. this is extortion and totally illegal.
If you have not done so, downgrade so that you aren't charged next time round:
Downgrade your iCloud storage - Apple Support
Then contact iTunes Support: explain the situation and ask for a refund:
If you have not done so, downgrade so that you aren't charged next time round:
Downgrade your iCloud storage - Apple Support
Then contact iTunes Support: explain the situation and ask for a refund:
icloud storage
