Sundance app kept charging me monthly fee despite the subscription being expired. Help!

I kept getting charged by the Sundance app and tried to cancel my subscription (auto after 30-day trial). There was not a way for me to unsubscribe it from my iTunes Account so I removed my credit card to stop the charges. That caused my account to be deactivated. I just reactivated my account and after seeing the app subscription being expired I put in my payment info and sure enough this app started charging me monthly fee! Such a scam. Anyone know how to stop it? Thx!