The advice is to call, not message. You need to interact with a live human being and, if the issue really is that you did not make a payment which was not due, that is fixable.
Just by way of example, is it possible that Chase transferred your credit balance to another deposit (checking) account or sent you a check for the credit balance, leaving you with a $0 balance followed by small charges which you then did not pay? It would be odd for Chase not to refund a credit balance after a billing cycle.