Hello Yes233,
Thanks for reaching out to the Apple Support Communities! We understand you are having some troubles with trying to upgrade your iCloud storage plan. We are happy to help provide some guidance.
When you navigate to Settings > [your name] > iCloud > Manage Storage > Change Storage Plan, does it show an expiration date below your current 200gb plan?
If you navigate to www.iCloud.com from a web browser, and go into your Account Settings, does is it show anything for your upgraded plan or current storage there?
We have some additional information about upgrading your iCloud storage plans in these following articles:
iCloud storage plans and pricing
Upgrade your iCloud storage plan
Keep us updated on how it goes and the answers to those questions.
Best Regards.