iCloud space not increasing

Does it show your iCloud upgrade when you go to settings, your name at the top, iCloud?

Maybe you are confusing iCloud storage with device storage. Upgrading your iCloud storage does not increase device storage. Please see: What's the difference between device storage and iCloud storage? - Apple Support

I had increase iCloud storage with 100gb extended plans

If you have upgraded iCloud+ plan, once your request for iCloud+ has been activated, you should receive an invoice in your email box.

Check -> Go to -> Settings -> your name -> iCloud -> if you see 50 GB (or 200 GB or 2 TB) then you have an iCloud subscription.

If you have an iCloud subscription, you will receive a monthly bill from Apple, check your email box.

See also the following Apple articles:

How to use iCloud on iPhone -> How to use iCloud on iPhone – Apple Support (UK)

Manage your iCloud storage -> Manage your iCloud storage - Apple Support

Watch: