Read this support article to learn how to...
"Downgrade or cancel your iCloud storage plan" on an iOS device, a Mac, or a PC.
Click here --> https://support.apple.com/HT207594
"If you can't click Done, make sure you are signed in with the same Apple ID as your iCloud storage plan. You can also try following these steps on a different device. If you still need help, contact Apple Support ( https://getsupport.apple.com/?caller=cups&PGF=PGF63006&category_id=SC0060 )."
For some people "Done" does not show, in which case a person found this solution worked for them: https://communities.apple.com/de/thread/250533579 = 'Click on the same option you currently have, then click accept. Then go back to the selection window and select the downgrade you wish and click accept.'
if that does not work, contact Apple:
Report A Problem; click here --> https://reportaproblem.apple.com/?s=6
or:
Click here --> https://support.apple.com/choose-country-region/media-services Select your country, then a product.
To get more information about the "Apple Trade In" service click on the link --> https://www.apple.com/shop/trade-in - Read the FAQ at the very bottom.
