Why can't I downgrade my storage

Hello jayjay0234,

After reviewing your post, it sounds like you are not able to pick an iCloud storage option. I would recommend that you read this article, it may be able to help the issue.

If you are not able to make the selection on one device you can try other devices.

iCloud storage upgrades and downgrades - Apple Support

Downgrade your iCloud storage plan

You can decrease the amount of storage by selecting a new plan right from your iPhone, iPad, iPod, Mac, or PC (for example, a 20 GB plan to replace a 200 GB plan). The downgrade will take effect after your current monthly or annual subscription ends.

iOS:

1. If you're using iOS 8, go to Settings > iCloud > Storage. If you're using an earlier version of iOS, go to Settings > iCloud > Storage & Backup.
2. Tap Change Storage Plan.
3. Tap Downgrade Options and enter your Apple ID password.
4. Choose a different plan to use when your current storage plan expires.
5. Tap Done.
   

OS X:

1. Choose Apple menu > System Preferences, then click iCloud.
2. Click Manage in the lower-right corner.
3. Click Change Storage Plan in the upper-right corner.
4. Click Downgrade Options.
5. Enter your Apple ID password, then click Manage.
6. Choose a different plan to use when your current storage plan expires.
7. Click Done.
   

Windows:

1. Open iCloud for Windows or iCloud Control Panel.
2. Click Storage if you're using iCloud for Windows. If you're using an earlier version of iCloud Control Panel, click Manage.
3. Click Change Storage Plan.
4. Click Downgrade Options.
5. Enter your Apple ID password, then click Manage.
6. Choose a different plan to use when your current storage plan expires.
7. Click Done.

Thanks for using Apple Support Communities.

Have a nice day,

Mario