How do I cancel our subscription?

We no longer use JotForm and we wish to cancel. It runs out on 9 November 2015 and I can't change my credit card details.

How do we cancel our subscription?

I tried downgrading to a Starter plan but I get this error

Error cancelling your subscription.
Please get in contact with our support team.Sorry for the inconvenience.

Support team links to this forum.

According to our records the subscription was canceled successfully. So the subscription reference number     :75836806 should not charge your CC anymore.