Q: how do i cancel storage upgrade for i cloud

Hi there gayneln,

You may find the information in the article below helpful.

iCloud: Cancel your storage upgrade 

If you upgrade or renew your storage but no longer need it, you can cancel. If you cancel your storage plan within 15 days of an upgrade or within 45 days after a yearly payment, you can contact Apple for a full refund. After this period, you can downgrade your storage for the following year.

-Griff W.