Cancel my subscription from another country

I’ve been trying to cancel my account since July when I moved to the United States. I explained I was moving and I deregistered and submitted the form, providing the offer letter from my current school ,filled the information they asked,but Never heard back and never received an phone call until I got an e-mail just now that they had withdrawn another 31.5 euros from my bank account today.  I was really furious and I want to the staff to act more sufficiently. Is there any way to stop this other than shutting down my bank account?