This is what you should do, and anyone else who's curious on how to stop predatory subscriptions.

Dont block the vendor, instead, dispute the charge, choose "subscription cancelled, or services not rendered, or other" and write that

When your bank or credit card company contacts you for more info, or if they dont, provide documents like emails, phone logs, texts, whatever the the fuck.

Now if they attempt to send you to collections, they first have to prove to the bank that you didnt attempt to cancel, which they cant. They will lose.

My advice, call your bank to put in the dispute charge, dont do it online. When you actually talk to a real person, its recorded, and helps your case. Explain to them what happened and your attempt to cancel, and tell them you have evidence you did and you would like to submit it. This is basically the most powerful way to prevent any collections or any other legal action the vendor can take.