Hi Yosemitebug,
Thanks for using Apple Support Communities. It sounds like you're having trouble upgrading your iCloud Storage. We're happy to help.
We see that you came from this article: Upgrade to iCloud+ - Apple Support
That link provides the correct steps for doing so. If you haven't already, try restarting your device before following those steps again.
Should the issue persist, try signing out of, and then back into your Apple ID. You can do so by following these steps: Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac - Apple Support
If the above doesn't resolve the issue, contact Apple Support.
Take care.