[sandreas]

I would first document the process with screenshots and video to prove you have failed to unsubscribe because of technical problems. Show multiple ways you tried.

Add further documentation by filing a ticket setting a deadline to get back your money, unsubscribe you and otherwise you will chargeback.

If you can afford it: Contact a lawyer in case you may get sued and ask for instructions. Maybe he tells you to chargeback the money.

[solardev]

It's not worth that hassle. Probably the credit card company will just automatically grant your request because it's a such a low dollar amount and not worth an investigation, much less a lawyer. Probably nobody at Twitter is left to fight it either.