Downgrade icloud
I no longer have an iPhone, and I don't know how to cancel my icloud + subscription or downgrade back to the original storage.
I logged into my icloud through icloud.com on my samsung
iPhone 6s Plus
Question marked as
It's a pity you have discarded your device because that's the most direct way to cancel iCloud+
However, there are other options and Apple describes them all in Downgrade or cancel your iCloud+ plan - Apple Support - which is to downgrade your plan to the free 5GB plan, at which point billing will cease.
You can sign into your iCloud account on a computer. If you have a Mac can sign into iCloud system preferences/settings and downgrade your plan there. A Windows computer will require you to install iCloud for Windows and to sign in with your Apple ID credentials.
The option of last resort, as noted in the linked document, is to contact Apple Support. This will take you to the Billings and Subscriptions support pages. Choose the options as appropriate.