Why can't I cancel my iCloud subscription and download apps from the App Store?

Hello. I can't cancel my iCloud subscription. I don't have a unsubscribe button. Are you aware of such a problem? The problems started when downloading apps from the AppStore. I couldn't download the free apps because they asked me for my card details and cvv. I tried to enter the card details, and they were certainly correct, but they were not accepted. I bought a new iPhone and logged into my Apple account, but the problems continued. I've been charged 2.5 dollars, and I don't understand why! A fee is charged for an iCloud subscription on the 13th of each month, which means that it has already been charged this month (in April). I tried to cancel my subscription, but I just don't have a cancel button. There is no iCloud subscription in my subscriptions. Help, I can't download anything, and they're charging me money. I am from Belarus.

[Re-Titled by Moderator]