Downgrading iCloud Storage

Hello

I'm trying to downgrade my subscription. To do so, I deleted everything from my account (pictures, emails, documents). I went from 45 g to the under 5 allowed for free billing. I had purchased the ,99$ plan. I've changed phones and I now want to cancel my subscription. I've done all the required steps, but when I have to confirm/accept, I can't click on accept (the button isn't active). Can someone help me out??