I would like to cancel my itunes

iTunes is an application. You can't "cancel" an application.

Do you mean Apple Music?

Please click on this link to learn "How to cancel a subscription from Apple" ➔ https://support.apple.com/HT202039

Note:

• "If you don’t see Cancel Subscription, then the subscription is already canceled and won't renew." An "Expires" date (instead of "Renews") means the current subscription will just run until then. "Resubscribe" is just in case you change your mind about having it end.

• Deleting an app does not cancel a subscription.

• If you don’t cancel trials more than 24 hours before your renewal date, your subscription might renew.

• If you don't have an Apple device, see the options near the very bottom of the support document.

"If the subscription that you want to cancel is not listed", click here ➔ https://support.apple.com/HT212052

If you still can't find a subscription, contact Apple Support using the link at the end of the support article.

If you still have problems:

Click here ➔ https://support.apple.com/choose-country-region/media-services Select your country, then a product.

Or: Contact Apple for support and service ➔ "See a list of Apple phone numbers around the world."

Click here ➔ https://support.apple.com/HT201232

Click on this link to see 'How to cancel Apple Music' on the web. ➔ https://support.apple.com/HT212047

Your initial post was misleading. :-/ Storage has nothing to do with iTunes.

Click on the link to read how to "Downgrade or cancel your iCloud storage plan" on an iOS device, a Mac, or a PC. --> https://support.apple.com/HT207594

See if anything here helps.

Downgrade your iCloud storage.   

Oh great. Another bait-and-switch topic. A waste of my time. :-(