Whether YOU think it is or not, or intended it as such, the fact it, taking money without the appropriate agreement in advance is STEALING. Zigner characterized it exactly correctly.
If you accepted orders based on other means to pay, and they fail to pay, you can certainly demand payment. But you can't just make up a check because you know their account number, even though if they issued a check, that would be payment. You can't just make up a card charge, even though if they authorized the charge, that would be payment. You CAN refuse to take future orders from them ... even prepaid ones.
As for charging much later in time, you will need to refer to your merchant agreement.